Recent Electroanalytical Studies of Metal-Organic Frameworks: A Mini-Review.

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Recent Electroanalytical Studies of Metal–Organic Frameworks: A Mini-Review a

a

Lida Fotouhi & Maryam Naseri a

Department of Chemistry, Faculty of Physics & Chemistry, Alzahra University, Tehran, Iran. Accepted author version posted online: 17 Jul 2015.

To cite this article: Lida Fotouhi & Maryam Naseri (2015): Recent Electroanalytical Studies of Metal–Organic Frameworks: A Mini-Review, Critical Reviews in Analytical Chemistry, DOI: 10.1080/10408347.2015.1063978 To link to this article: http://dx.doi.org/10.1080/10408347.2015.1063978

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ACCEPTED MANUSCRIPT Recent electroanalytical studies of metal-organic frameworks: A mini-review Lida Fotouhi*, Maryam Naseri Department of Chemistry, Faculty of Physics & Chemistry, Alzahra University, Tehran, Iran P. Code 1993891176, Tehran, Iran *

Corresponding author at: Department of Chemistry, Faculty of Physics & Chemistry, Alzahra

Downloaded by [New York University] at 22:36 22 July 2015

University, P. Code 1993891176, Tehran, Iran. Tel.: +98 21 88044040; Fax: +98 21 88035187. E-mail address: [email protected] (Lida Fotouhi). Abstract Metal–organic frameworks (MOFs) are attracting considerable attention because of their unique structural properties, such as high surface areas, tunable pore sizes, and open metal sites, which enable them to have potential applications in gas storage, catalysis, sensors, drug release, and separation. Also, MOFs can be fabricated and functionalized as electrochemically functional frameworks with perfect electrochemical properties and electrocatalytic activities. This review focuses on the electroanalytical applications of MOFs between 2010 and 2014 years. Keywords Electrodeposit, Photoelectrochemical sensors, Electrocatalytic activity, Cyclic voltammetry, Linear sweep voltammetry, Biological molecule.

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ACCEPTED MANUSCRIPT Introduction Research on crystalline porous materials has received tremendous attention in recent years. MOFs are a new member in the vast field of porous materials. The first MOFs are constituted by connecting metal ions with polytopic organic linkers (Yaghi, 1995) that allow combining the properties of both organic and inorganic porous materials (Klein et al., 2009). Research on these compounds, as a class of novel porous materials, is expanding very rapidly due to their unique


properties such as high specific surface area with microporosity (Farha and Hupp, 2010), structural flexibility, high long-range order, and high potential to be functionalized and modified the frameworks in countless ways (Phan et al., 2010). An exponential increase in the number of publications in the MOF area within the last 15 years is given in Fig. 1. Several preparation methods for the formation of MOFs have been developed throughout the years (Stock and Biswas, 2011). During the recent years, traditional approaches such as hydro- and solvothermal synthesis have been complemented with other methods; ionothermal (Lin et al., 2007; Parnham and Morris, 2007; Wu et al., 2011), slow base diffusion, microwave assisted (Cho et al., 2012; Wu et al., 2013; Klinowski et al., 2011), snochemical (Jung et al., 2010; Tahmasian et al., 2013; Karizi et al., 2014; Alavi and Morsali, 2014), electrochemical, and mechanochemical (Fujii et al., 2010; Klimakow et al., 2010; Schlesinger et al., 2010; Yang et al., 2011) syntheses. Among these, electrochemical method has more advantages such as simple procedure, ease of handing, higher yield efficiency, high purity of products and very short reaction time (Al‐Kutubi et al., 2015). For the first time Müller et al. synthesized Cu-MOF by electrochemical method in 2006 (Mueller et al., 2006). The electrochemical reaction occurred inside an electrochemical cell containing Cu-plates as electrode materials and the carboxylate 2

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ACCEPTED MANUSCRIPT linker (1,3,5-benzenetricarboxylic acid) dissolved in methanol (time: 150 min, voltage: 12-19 V, currency: 1.3 A). Few years later, a fast method for growing the Cu 3(BTC)2 (BTC = benzene1,3,5-tricarboxylate) as a coating or thin film using the electrochemical method was published (Ameloot et al., 2009). By varying the voltage, the concentration of metal ions was changed and the crystal sizes could be controlled. Dinca et al. (Li and Dinca, 2011) demonstrated electrodeposition of Zn4O(BDC)3 (BDC = 1,4-benzene dicarboxylate) on fluorine-doped tin


oxide (FTO) by dissolving Zn(NO3)2 and H2BDC in a DMF/H2O solvent mixture containing (NBu4)PF6 electrolyte at a constant potential of -1.6 V for 15 min. MOFs based on different metals (Cu, Zn, and Al) and linker connectivities (bi- and tridentate carboxylic acids and imidazoles) were electrosynthesized via anodic dissolution (Martinez et al., 2012). In electrochemical MOF synthesis, metal salts are not required and therefore separation of anions such as NO3 - or Cl- from the synthesis solution is not needed prior to solvent recycle. Kulandainathan et al. reported the optimized condition for electrochemical synthesis of Cu3(BTC)2 and used Cu3(BTC)2 as a catalyst for chemical reduction of nitrophenol in the presence of excess NaBH4 (Kumar et al., 2013). Electrolysis was carried out in an electrochemical cell under constant voltage by anodically dissolving copper ion to link/bind with BTC molecules (organic linker). Recently, Liang et al. reported the electrosynthesis process for Zn-based MOF (Yang et al., 2015). They used an electrochemical cell containing Zn plate as the anode, Ti electrode as the cathode; and acrylamide, acrylic acid, and zinc sulfate solutions as the electrolyte. They used ceric ammonium nitrate as initiator of the reaction and provided a new way for synthesis of MOFs porous materials by introducing the role of free radicals, OH •.

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ACCEPTED MANUSCRIPT MOFs, in general, have two disadvantages. MOFs, especially those based on carboxylates and zinc clusters, lose their crystallinity in protic solvents (methanol/ethanol) and aqueous media even at room temperature. This property is a result of the labile metal-oxygen bonding. This bond is easily dissociated in the reactive medium and this causes the frameworks to lose their crystallinity (DeCoste et al., 2013; Tan et al., 2012). This property limits the application of MOFs to anhydrous conditions. The other disadvantage is the limited number of


subunits of MOFs called, secondary building units (SBUs). The predictability of the topology of a MOF is an advantage, in comparison with other porous materials. However, to obtain new topologies sometimes requires suitable SBUs. Although many SBUs have been reported and have been applied in the synthesis of MOFs, the limitation in SBU generally can be a limitation in MOF design. Although initial research on MOFs was mainly driven by their application as gas storage (CH4, H2 and CO2) materials (Sumida et al., 2011; Zheng et al., 2013; Suh et al., 2011), a range of other potential applications were proposed and demonstrated, including catalysis (Fu et al., 2012; Jahan et al., 2012; Senthil Kumar et al., 2012; Liu et al., 2014), drug release (An et al., 2009), sensor technology (Lu and Hupp, 2010; Kreno et al., 2012), separation (Haldoupis et al., 2010; Shah et al., 2012), embedding of nanoparticles (Huang et al., 2012), and supercapacitors (Díaz et al., 2012; Ke et al., 2015). In particular, high surface area, porosity, and chemical tenability of MOFs allows to load these compounds with catalytically active metal nanoparticles (NPs) such as palladium, gold, copper, and ruthenium to achieve an increased catalytic efficiency (Turner et al., 2008). The MOFs can act as a support to control shape and size of NPs to improve the activity and to develop highly active electrocatalysts to be used in electrochemistry (Solla4

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ACCEPTED MANUSCRIPT Gullón et al., 2011). Haruta et al. reported an effective method for direct deposition of Au clusters onto several kinds of porous coordination polymers including MOF-5 (Ishida et al., 2008). Au was deposited by grinding the solids with organogold complex in the absence of organic solvents. Gold clusters on MOFs exhibit noticeably high catalytic activity in liquid phase alcohol oxidation even in the absence of base. Kim et al. described the formation of Ni particles in mesoporous MOF-1 (MesMOF-1) and demonstrated reduction of small molecules catalyzed


by the immobilized Ni-nanoparticles in MesMOF-1(Park et al., 2010). Recently, several investigations have begun exploring the potential of MOFs as chemical sensors (Kreno et al., 2012; Hu et al., 2014). The exceptional tenability of MOF structures and properties constitute an important advantage over other conventional chemo-sensory materials. So, MOF-based sensors have significant potential for developing powerful analytical techniques for determination of biomolecules. Depending on the type of metal ions and ligands, MOFs can be electrochemically active and have electrocatalytic activity (Domenech et al., 2007; Morozan and Jaouen, 2012; Halls et al., 2013). This review focuses on the electroanalytical application of MOFs. First, we briefly explain electrocatalytic activities of some MOFs and then a series of MOF-based electrochemical and photoelectrochemiacl sensors are summarized for their analytical application in selective detection of small molecules, metal ions, and other biologically important targets. Electrocatalysis activities of MOFs Electrocatalytic activity of a Cu-based MOF for oxidative carbonylation of methanol was studied by Gao et al. (Fig. 2) (Jia et al., 2013). They proposed a new catalytic mechanism for

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ACCEPTED MANUSCRIPT oxidative carbonylation of methanol (Fig. 3). The methanol group in the alkaline electrolyte was dissociated into H+ and CH3O−. The methoxy group was attached to the metal center of the MOF by nucleophilic (CH3O−) attack. Carbon monoxide also adsorbed onto the metal center of the MOF, while Cu(II) was reduced to Cu(I). This process involved insertion of CO into the CuO bond, which was the rate-determining step. The dimethyl carbonate (DMC) formed by CH3OCO− reacted rapidly with another CH3O− group, and Cu(I) could be oxidized back to


Cu(II) by virtue of electron transfer. Marken et al. (Babu et al., 2010) investigated the electrocatalytic activity of solid BasoliteTM F300 or Fe(BTC) immobilized onto graphite or platinum electrodes in both acidic and alkaline media. The Fe(III/II) redox process in aqueous acids is accompanied with a CE-type reduction dissolution process, which leads to rapid loss of Fe(BTC) from the electrode surface at acid concentration of 1 molL-1 or higher as follows: Fe  III  BTC  solid   3H  aq   Fe3  aq   H3BTC  aq  (1)

Fe3  aq   e  Fe2  aq  (2)

They observed an effective electrocatalysis for oxidation of hydroxide to O2 (anodic water splitting) in alkaline aqueous media after initial cycling of the potential into the reduction potential zone. They concluded that Fe(BTC) is electrochemically active in aqueous protic environement on platinium. This porous solid can be activated cathodically as an efficient oxygen evolution and water splitting electrocatalyst.

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ACCEPTED MANUSCRIPT Yin et al. (Wang et al., 2014) synthesized a mixed metal ion MOF(Fe/Co) and investigated its bifunctional catalytic activities toward oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in alkaline electrolyte by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). It was shown that OER activation of SP (Super P) at 0.75V was negligible, while the current density of MOF(Fe/Co)+SP sample increased significantly (79 times higher than that of SP at 0.9V). ORR results showed the same behavior as OER, the


current density of the MOF(Fe/Co) +SP sample was considerably higher than SP sample (17 times higher than that of SP at -0.3V). The OER and ORR results concluded that MOF(Fe/Co)+SP exhibits excellent bifunctional catalytic activities due to the high specific surface area and microporous structure of MOF(Fe/Co). The rotate disk electrode (RDE) results indicated that the two-electron pathway of oxygen reduction occurred at -0.35 to -0.55 V, with the four-electron pathway gradually dominating as the potential became more negative. MOFs are good candidates for ethanol oxidation in fuel cell but a small number of MOF materials display high electron conductivity, which is essential for electrocatalytic reactions. Kitagawa et al. (Yang et al., 2010) reported N,N’-bis (2-hydroxyethyl) dithiooxamidato copper (II) [(HOC2H4)2dtoaCu] as a catalyst for ethanol electrooxidation reactions (EERs). This material is a good proton and electron conductor with proton conductivity of 3.3×10 4 Scm-1. The ethanol sorption isotherms of [(HOC2H4)2dtoaCu] showed that this MOF adsorb about 0.8 mol of ethanol per 1.0 mol of the target compound; suggesting a strong chemical interaction between [(HOC2H4)2dtoaCu] and ethanol molecules. A quasi-reversible oxidation couple with a halfwave potential of 0.35 V (CuI/CuII) and an irreversible wave with Ep=0.71 V (CuII/CuIII) were

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ACCEPTED MANUSCRIPT observed in its cyclic voltammogram. Peak currents were enhanced by adding ethanol. The ethanol electrooxidation on this MOF material is dependent on the ethanol concentration. Pyridine-functionalized graphene (reduce graphene oxide (r-GO)) can be used as a building block in the assembly of MOF. Loh et al. synthesized a hybrid MOF by adding pyridinium dye functionalized r-GO sheets to the iron-porphyrin framework ((Fe-P)n MOF)


(Jahan et al., 2012) (Fig. 4). The effective surface area of glassy carbon electrode (GCE) and (Gdye 50 wt% - FeP)nMOF/GCE was estimated by CV using Fe(CN)63-/4- in KCl. The electroactive surface area of (G-dye 50 wt% - FeP)n MOF (10.98 × 10-2 cm2) was nearly 20 times larger than that of bare GCE ( 0.55 × 10-2 cm2). Incorporation of G-dye increased electroactive surface area of the electrode and enhanced the charge transfer kinetics. The overpotential for ORR in (G-dye 50 wt % -FeP)n MOF-modified cathode is shifted positively by 120 mV compared to GO. These improvements in catalytic activities can be explained by the synergistic effects of framework porosity, a larger bond polarity due to nitrogen ligand in the G-dye, and the catalytically active iron-porphyrin in the structure of the hybrid MOF. Kulandainathan et al. demonstrated the uniform film of Cu3(BTC)2 on GCE as an efficient electrocatalyst for selective reduction of carbon dioxide (Senthil Kumar et al., 2012). Cu3(BTC)2 was synthesized electrochemically under constant voltage electrolysis using the organic linker (BTC) and supporting electrolyte (tetrabutylammonium tetrafluoroborate (TBATFB)) in methanol solution. The cyclic voltammetric response of Cu 3(BTC)2 indicated that the copper is in the Cu2+ ionic state, which is consistent with X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results, whereas a redox peak behavior was not observed for

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ACCEPTED MANUSCRIPT Cu electrode. An increased current with a positive cathodic potential was reported for reduction of CO2 at Cu3(BTC)2 coated GCE than that for bare GCE due to the electrocatalytic activity of Cu3(BTC)2. This is due to the tendency of absorbing more CO2 in the pores of Cu3(BTC)2 and there is a possibility for electrochemical reduction of the compressed gas inside the pores via heterogeneous electron transfer between Cu3(BTC)2 and CO2 molecule.


Electroanalysis activities of MOFs Electrochemical sensing applications of MOFs High porosity, ordered structures, and adjustable chemical functionality make MOFs promising modifiers in electrochemical analysis, providing novel electrochemical sensors. Bagheri et al. (Hosseini et al., 2013) fabricated a novel electrochemical sensor based on Au-SH-SiO2 nanoparticles (SH: 3-(trimethoxysilyl)-1-propanethiol) on MOF for electrocatalytic oxidation and detection of L-cysteine. The electrochemical response of the Au-SH-SiO2 @ Cu-MOF/GCE in the absence of L-cysteine showed one anodic peak at +0.01V (corresponding to the oxidation of copper metal) with its cathodic peak at -0.23V (due to reduction of copper ion to copper metal). This sensor showed electrocatalytic activity towards L-crystein oxidation (0.6 V), where oxidation peak current increased and overpotential decreased. They reported a linear calibration plot in the range of 0.02-300 μmol L-1 cysteine with detection limit of 0.008 μmol L -1. An electrochemical sensor fabricated based on a carbon past electrode (CPE) modified with ZnO4(BDC)3(MOF-5) was developed for sensitive determination of lead (Wang et al., 2013) (inset Fig. 5). Zn-based MOFs are water sensitive and lose their large surface area in water; so, a bulk modification of CPE was prepared instead of plating a film on the electrode

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ACCEPTED MANUSCRIPT surface. The lead was determined in two steps; accumulation of the lead ions adsorbed at the modified electrode surface (300 s at -0.9 V), followed by electrochemical detection of the preconcentrated species using differential pulse stripping voltammetry. It was found that anodic peak current of lead at MOF-5 modified electrode was five times of that at the unmodified electrode with an anodic shift of potential to -0.42 V (Fig. 5). A good linear relationship between


anodic peak current and the lead concentration was obtained (Table 1). Wang et al. (Wang et al., 2014) prepared amino functionalized metal-organic frameworks (NH2–Cu3(BTC)2) and introduced a novel electrode modifier for determination of trace levels of lead. They reported that Cu3(BTC)2 modified GCE gave a signal at -0.525 V because of the absorbing effect of Cu3(BTC)2, while a remarkable increase in response signal was observed on NH2–Cu3(BTC)2 modified GCE. The proposed mechanism for stripping voltammetric measurement was reported as follows: first, lead ions accumulate from the solution phase onto the surface of the NH2-Cu3(BTC)2/GCE by selective complexation with free functional amino group to form a metal-ligand complex, and then the complexed ions accumulated in the modifying layer are reduced by applying a constant voltage of -0.9 V in the accumulation step. Lead is then electrochemically stripped back into the solution by scanning toward positive potential using the differential pulse voltammetric method. Second, lead ions can penetrate into Cu3(BTC)2 channels, and the shape and size of the pores lead to shape- and size-selectivity over the metal ions, which may accumulate. The synergistic combinations of these effects lead to a higher lead accumulation on the surface of NH2–Cu3(BTC)2/GCE. Under the optimal conditions, a linear calibration curve was obtained in the concentration range from 1.0×10 -8 to 5.0×10-7 mol

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ACCEPTED MANUSCRIPT L-1 (R2=0.9951). They investigated the sensor applicability by determining lead in some solutions, in which their results were in good agreement with certified values. MIL-101(Cr3X(H2O)2O(BDC)3; X = F, OH) can be used to form a novel CPE with excellent electroanalytical performance for applications in electrochemical sensors. Since the structure of MIL-101 consists of μ3-oxo bridged chromium (III)-trimers cross-linked by


terephthalate groups, the metal ions and terephthalate groups can provide the channel for charge transfer. Li et al. (Li et al., 2013) reported a MIL-CPE for investigation of the electrocatalytic oxidation of dopamine (DA) and uric acid (UA) by electrochemical impedance spectroscopy (EIS) and CV. The CV responses of CPE and MIL-CPE show no redox peak in the absent of DA and UA; so, MIL-101 (Cr) itself is totally inert in terms of direct electrochemistry in phosphate buffered solution (PBS). Meanwhile, two well-defined peaks were observed on MIL-CPE in the presence of DA and UA. They concluded that electrocatalysis towards DA and UA is attributed to contact electrocatalysis from MIL-101 with decreasing the overpotential accompanied by enhanced current response and peak separation. They reported linear concentration ranges for DA and UA (Table 1). Guo et al. (Zhang et al., 2014) investigated electrochemical stability properties of pure Cu-MOFs and Cu-MOF-MPC (macroporous carbon) composite by cyclic voltammetry. The CVs of Cu-MOFs/GCE show one pair of redox wave at a formal potential of ca. -0.15 V, which is ascribed to the redox process of CuII/I in Cu3(BTC)2. Their results showed that the unstable redox property of Cu-MOFs is due to its instability in aqueous media. MPC supports can enhance the water stability and thereby increase the electrochemical stability of Cu-MOFs.

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ACCEPTED MANUSCRIPT Cu-MOFs-MPC not only promote development of thermally, aqueous, and electrochemically stable porous composite materials, but also hold great promise for design of biomolecular electrochemical sensors in neutral solutions. This composite displayed excellent electrocatalytic ability for reduction of hemoglobin (Hb) and oxidation of ascorbic acid (AA) (Table 1). Combining the porosity, high surface area of MOFs and electrocatalytic properties of


metal NPs could open up a range of new applications for these materials and could provide a new approach in electrode surface modification for designing new electrochemical sensors. Bagheri et al. (Hosseini et al., 2013) described a novel sensor for electrocatalytic oxidation and determination of hydrazine based on combination of unique properties of the MOFs and Au-SHSiO2 nanoparticles. The CV response of Cu-MOF/GCE consisted of one anodic peak at +0.01 V during the anodic scan, corresponding to oxidation of Cu metal to Cu oxide species, and a cathodic peak approximately at -0.23 V that is related to reduction of Cu oxide species to Cu metal. Similar to voltammetric response of Cu-MOF/GCE, the CV response of Au-SHSiO2@Cu-MOF/GCE in PBS showed one oxidation and one reduction peaks, for which their peak currents were larger as compared with the redox peak currents of Cu-MOF/GCE. They reported that the increased peak current was probably related to oxidation and reduction of Au NPs overlapped with MOF peaks. The potential application of this sensor was evaluated for electrooxidation and detection of hydrazine by CV. The oxidation of hydrazine requires very high positive overpotentials at bare GCE and no significant oxidation peak was observed on CuMOF/GCE. While the electrode surface was modified with the Au-SH-SiO2 @Cu-MOF films, a well-defined anodic peak at 0.53 V with a remarkable increase in peak current was observed for oxidation of hydrazine; indicating a significant electrocatalytic effect and a good electrochemical 12

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ACCEPTED MANUSCRIPT response to hydrazine. A good linear relationship was obtained between oxidation current and concentration of hydrazine (Table 1). A new Cu-MOF, [Cu(adp)(BIB)(H2O)]n (BIB= 1,4-bisimidazolebenzene; H2adp= adipic acid), was synthesized under hydrothermal condition by Xu et al. (Zhang et al., 2013). Its electrochemical behavior was investigated as a Cu-MOF modified electrode, in which a high


electrocatalytic activity toward H2O2 oxidation was shown by increasing anodic peak current. H2O2 was oxidized to O2 by [(adp)(BIB)CuIII-OH], while [(adp)(BIB)CuII-OH2] was regenerated by capturing an electron. An excellent linear relationship of the anodic peak current I pa with H2O2 concentration was obtained in the alkaline solution with a detection limit of 0.068 μmol L -1 (Table 1). Wen et al. (Wen et al., 2010) synthesized a new conjugated MOF based on 2,2ʹ,4,4ʹbiphenyltetracarboxylic acid with a uninodal five-connected hexagonal boron nitride net. These conjugated MOFs with high dimensionality were considered as good solid-phase extraction materials capable of adsorbing and concentrating trace organophosphate pesticide (OP) compounds and sorbents of nitroaromatic OPs by direct physical adsorption. Methyl parathion (MP) was selected as a model to demonstrate the effectiveness of this MOF for detecting electroactive OP compounds. Detection of MP included two main steps: (1) MP adsorption; (2) electrochemical stripping detection of adsorbed MP on MOF/GCE by square-wave voltammetry (SWV) (Fig. 6). The SWV response of adsorbed MP at MOF/GCE displayed well-defined peaks, proportional to the concentration of the corresponding MP (Table 1).

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ACCEPTED MANUSCRIPT Polyoxometalates (POMs) are optimal choices of chemical species for incorporation into the pores of MOFs. Fernandes et al. (Fernandes et al., 2014) prepared the novel SiW11 Fe@MIL101 composite material by incorporation of the iron-substituted silicotungstate anion (as a POM compound) into the mesoporous framework of MIL-101(Cr). The CVs of the SiW11 Fe@MIL101-modified pyrolytic graphite electrode (PGE) in a pH 2.5 H 2SO4/Na2SO4 buffer solution showed four pairs of peaks: EpcCr= 0.261 V, EpcFe= -0.149 V, EpcW1= -0.633 V, and EpcW2= -0.751


V versus Ag/AgCl (Fig. 7). The characteristic peaks of the POM in the composite material were identified from CVs of the individual compounds (SiW11Fe and MIL-101(Cr)). Peaks W1 and W2 were assigned to the W-centered reduction processes (WVI→WV) and peak Fe was assigned to the iron-reduction process (FeIII→FeII). Peak Cr in the composite material was attributed to the Cr centers in MIL-101(Cr). The SiW11Fe@MIL-101-modified electrode showed excellent electrocatalytic properties for both reduction of nitrite and iodate, and oxidation of ascorbic acid (AA). The linear range for the catalytic current extends up to nitrite, iodate, and ascorbic acid concentrations of 0.6×10 -3, 0.6×10-3, and 0.3×10-3 mol L-1 for SiW11Fe@MIL-101, respectively, with detection limits of 3.22×10-5, 3.03×10-5, and 3.07×10-5 mol L-1. Li et al. (Zhou et al., 2014) constructed a novel non-enzymatic sensor based on the Cubipy-BTC and multiwalled carbon nanotubes (MWCNTs) composite. MOFs have unique properties including large surface area; so that intercalation of Cu-bipy-BTC could enlarge the surface area of MWCNTs. Their CV results showed a couple of well-defined redox peaks in a phosphate buffer solution (pH = 6.0), ascribed to the redox process of CuII/I in the Cu-bipy-BTC. Application of this sensor was evaluated for electrochemical detection of hydrogen peroxide. The cyclic voltammetric studies indicated that combination of Cu-bipy-BTC and MWCNTs 14

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ACCEPTED MANUSCRIPT improves sensitivity of H2O2 detection, which may result from the synergistic effect of MWCNTs and Cu-bipy-BTC. For quantitative analysis of the Cu-bipy-BTC/MWCNTs/GCE sensor, LSV was used and a wide linear range with reasonable detection limit was reported (Table 1). Zhang et al. (Zhang et al., 2015) fabricated a nanocrystal Co-MOF composite with MPC


incorporation by a one-step hydrothermal treatment of the Co-MOF precursor mixture and MPC. EIS curves of Co-MOF-MPC-x-GCE (x = 1, 2, and 3 and represents different MPC contents) displayed that after modification with MPC, the semicircle diameter of Co-MOF–MPC-x–GCE decreases. They claimed MPC can form good electron pathways between the electrode and electrolyte. To evaluate electrochemical activity of the Co-MOF-MPC composites, they chose hydrazine and nitrobenzene (Table 1). Photoelectrochemical sensing applications of MOFs Porous MOFs can be used as electrode modifiers in electroanalytical chemistry. MOF thin films deposited onto a working electrode such as GCE might be useful for many photoelectrochemical applications. Hu et al. (Hou et al., 2012) synthesized MOF-5 thin films on a GCE with 4carboxyphenyl as a covalent linker, and used this modified electrode as a photoelectrochemical sensor for detection of ascorbic acid. The photocurrent generation mechanism of a MOF-5 modified GCE is shown in Fig. 8. The concentration of AA was determined by measuring the photocurrent originating from the electron transfer. Photocurrent increased linearity as the AA concentration increased from 0.05 to 1.4 mmol L-1. Kuang et al. (Zhan et al., 2013) synthesized ZnO@zeolitic imidazolate frameworks-8 (ZIF-8) nanorods and nanotubes with core-shell

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ACCEPTED MANUSCRIPT heterostructures. ZnO nanorod and nanotube were used as templates that can also provide Zn 2+ ions for the formation of ZIF-8 by dissolving them with the assistance of solvents. ZnO is a semiconductor with excellent photoelectric properties and is considered as a promising candidate for photovoltaic and photocatalysis applications. By combining with ZIF-8, ZnO@ZIF-8 nanorod arrays could show different photocurrent responses for hole scavengers at various sizes. The photocurrent response of the ZnO@ZIF-8 nanorod arrays is increased by addition of H2O2,


while it is reduced by addition of AA. They reported that such ZnO@ZIF-8 nanorod arrays were successfully applied to detection of H2O2 and AA and potentially have promising applications in many electronic devices including sensors. Hu et al. (Xu et al., 2014) used NH2-MIL-125(Ti) as a modifier to construct a photoelectrochemical sensor to detect traces Mn2+. Optical absorption of NH2-MIL-125(Ti) was investigated using UV–Vis spectroscopy. Diffuse reflectance UV/Vis spectra showed that NH 2MIL-125(Ti) had two absorption bands attributed to ATA2−Ti4+ → ATA−Ti3+ transition within the framework subunits. The absorption edge extended to around 500 nm, indicating that NH 2MIL-125(Ti) could absorb light in the visible region. They concluded that light irradiation could accelerate the interfacial charge-transfer process of NH2-MIL-125(Ti) and decrease the electron transfer resistance by recording EIS. Light irradiation caused a great increase in the stripping current (four times) on NH2-MIL-125(Ti)/CPE compared with the absence of light irradiation. A good linear relationship (R = 0.999) was reported between the peak currents and the concentration of Mn2+ over the range of 1.0×10−8 to 1.0×10−5 mol L-1 with the detection limit of 4.0×10−9 mol L-1.

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ACCEPTED MANUSCRIPT Conclusion MOFs are known for their high surface areas, tunable pore size, and adjustable internal surface properties which enable them to have potential applications in gas storage, catalysis, sensors, drug release, and separation. The organic–inorganic hybrid porous MOFs could be electrochemically active that depend on the type of metal ions and ligands. Advantage of high


porosity, porous structures, and adjustable chemical functionality of MOFs could make them as a promising modifier in electrochemical analysis and extend the field of applications of on electrochemistry sensors and detection variety of targets. Porous MOFs modified electrodes can also be used as photoelectrochemical sensors for detection metals and some important molecules. The concentration of analyte is determined by measuring the photocurrent originating from the electron transfer.

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ACCEPTED MANUSCRIPT References Alavi, M. A.; Morsali, A. Ultrasound assisted synthesis of {[Cu 2(BDC)2(dabco)]. 2DMF. 2H2O} nanostructures in the presence of modulator; New precursor to prepare nano copper oxides. Ultrason. Sonochem. 2014, 21(2), 674-680. Al‐Kutubi, H.; Gascon, J.; Sudhölter, E. JR.; Rassaei, L. Electrosynthesis of metal–organic


frameworks: challenges and opportunities. Chem. ElectroChem. 2015, 2(4), 462 – 474. Ameloot, R., L.; Stappers, J.; Fransaer, L.; Alaerts, B. F.; De Vos, D. E. Patterned growth of metal-organic framework coatings by electrochemical synthesis. Chem. Mater. 2009, 21(13), 2580-2582. An, J.; Geib, S. J.; Rosi, N. L. Cation-triggered drug release from a porous zinc−adeninate metal−organic framework. J. Am. Chem. Soc. 2009, 131(24), 8376-8377. Babu, K. F.; Kulandainathan, M.; Katsounaros, A.; I.; Rassaei,L.; Burrows, A. D.; Raithby P. R.; Marken F. Electrocatalytic activity of BasoliteTM F300 metal-organic-framework structures. Electrochem. Commun. 2010, 12(5), 632-635. Cho, H. Y.; Yang, D.; Kim, J.; Jeong, S. Y.; Ahn W. S. CO 2 adsorption and catalytic application of Co-MOF-74 synthesized by microwave heating. Catal. Today. 2012, 185(1): 35-40. DeCoste, J. B.; Peterson, G. W.; Jasuja, H.; Glover, T. G.; Huang, Y.; Walton, K. S. Stability and degradation mechanisms of metal–organic frameworks containing the Zr6O4(OH)4 secondary building unit. J. Mater. Chem. A 2013, 1(18), 5642-5650.

18

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Díaz, R.; M. Orcajo, G.; Botas, J. A.; Calleja, G.; Palma, J. Co8-MOF-5 as electrode for supercapacitors. Mater. Lett. 2012, 68, 126-128. Domenech, A.; García, H.; Doménech-Carbó, M.; Llabrés-i-Xamena, F. Electrochemistry of metal-organic frameworks: a description from the voltammetry of microparticles approach. J. Phys. Chem. C 2007, 111(37), 13701-13711.


Farha, O. K.; Hupp, J. T. Rational design, synthesis, purification, and activation of metal− organic Framework materials. Acc. Chem. Res. 2010, 43(8), 1166-1175. Fernandes, D. M.; Granadeiro, C. M.; Paes de Sousa, P. M.; Grazina, R.; Moura, J. J.; Silva, P.; Paz, A.; Filipe, A.; Cunha‐Silva L.; Balula S. S. SiW11Fe@ MIL‐101 (Cr) composite: A novel and versatile electrocatalyst. Chem. ElectroChem. 2014, 1(8), 1293-1300. Fu, Y.; Sun, D.; Chen, Y.; Huang, R.; Ding, Z.; Fu, X.; Li, Z. An amine‐functionalized titanium metal–organic framework photocatalyst with visible‐light‐induced activity for CO2 reduction. Angew. Chem. 2012, 124(14), 3420-3423. Fujii, K.; Lazuen Garay, A.; Hill, J.; Sbircea, E.; Pan, Z.; Xu, M.; Apperley, D. C.; James S. L.; Harris K. D. Direct structure elucidation by powder X-ray diffraction of a metal-organic framework material prepared by solvent-free grinding. Chem. Commun. 2010, 46(40), 75727574. Haldoupis, E.; Nair S.; Sholl D. S. Efficient calculation of diffusion limitations in metal organic framework materials: a tool for identifying materials for kinetic separations. J. Am. Chem. Soc. 2010, 132(21), 7528-7539.

19

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Halls, J. E.; Jiang, D.; Burrows, A. D.; Kulandainathanb, M. A.; Marken, F. Electrochemistry within metal-organic frameworks. Electrochemistry: Nanoelectrochemistry 2013, 12, 187-210. Hosseini, H.; Ahmar, H.; Dehghani, A.; Bagheri, A.; Fakhari, A. R.; Amini M. M. Au-SH-SiO2 nanoparticles supported on metal-organic framework (Au-SH-SiO2@ Cu-MOF) as a sensor for electrocatalytic oxidation and determination of hydrazine. Electrochim. Acta. 2013, 88, 301-309.


Hosseini, H.; Ahmar, H.; Dehghani, A.; Bagheri, A.; Tadjarodi, A.; Fakhari, A. R. A novel electrochemical sensor based on metal-organic framework for electro-catalytic oxidation of Lcysteine. Biosens. Bioelectron. 2013, 42, 426-429. Hou, C.; Peng,J.; Xu, Q.; Ji, Z.; Hu, X. Elaborate fabrication of MOF-5 thin films on a glassy carbon electrode (GCE) for photoelectrochemical sensors. R. Soc. Chem. Adv. 2012, 2(33), 12696. Huang, Y.; Liu, S.; Lin, Z.; Li, W.; Li, X.; Cao, R. Facile synthesis of palladium nanoparticles encapsulated in amine-functionalized mesoporous metal–organic frameworks and catalytic for dehalogenation of aryl chlorides. J. Catal. 2012, 292, 111-117. Hu, Z.; Deibert, B. J.; Li, J. Luminescent metal–organic frameworks for chemical sensing and explosive detection. Chem. Soc. Rev. 2014, 43(16), 5815-5840. Ishida, T.; Nagaoka, M.; Akita, T.; Haruta M. Deposition of gold clusters on porous coordination polymers by solid grinding and their catalytic activity in aerobic oxidation of alcohols. Chem. Eur. J. 2008, 14(28), 8456-8460.

20

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Jahan, M.; Bao, Q.; Loh K. P. Electrocatalytically active graphene–porphyrin MOF composite for oxygen reduction reaction. J. Am. Chem. Soc. 2012, 134(15) 6707-6713. Jia, G.; Gao, Y.; Zhang, W.; Wang, H.; Cao, Z.; Li, C.; Liu, J. (2013). Metal-organic frameworks as heterogeneous catalysts for electrocatalytic oxidative carbonylation of methanol to dimethyl carbonate. Electrochem. Commun. 2013, 34, 211-214.


Jung, D. W.; Yang, D. A.; Kim, J.; Kim, J.; Ahn, W. S. Facile synthesis of MOF-177 by a sonochemical method using 1-methyl-2-pyrrolidinone as a solvent. Dalton Trans. 2010, 39(11) 2883-2887. Karizi, F. Z.; Safarifard , V.; Khani, S. K.; Morsali, A. Ultrasound-assisted synthesis of nanostructured 3D zinc (II) metal–organic polymer: Precursor for the fabrication of ZnO nanostructure. Ultrason. Sonochem. 2014, 23, 238-245. Ke, F. S.; Wu, Y. S.; Deng, H. Metal-organic frameworks for lithium ion batteries and supercapacitors. J. Solid State Chem. 2015, 223, 109-121. Klein, N.; Senkovska,I.; Gedrich, K.; Stoeck, U.; Henschel, A.; Mueller, U.; Kaskel, S. A mesoporous metal-organic framework. Angew. Chem. Int. Ed. Engl. 2009, 48(52), 9954-9957. Klimakow, M.; Klobes, P.; Th nemann, A. F.; Rademann, K.; mmerling, F. Mechanochemical synthesis of metal−organic frameworks: a fast and facile approach toward quantitative yields and high specific surface areas. Chem. Mater. 2010, 22(18), 5216-5221. Klinowski, J.; Paz, F. A.; Silva, P.; Rocha, J. Microwave-assisted synthesis of metal-organic frameworks. Dalton Trans. 2011, 40(2), 321-330. 21

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Kreno, L. E.; Leong, K.; Farha, O. K.; Allendorf, M.; Van Duyne, R. P.; Hupp, J. T. Metal– organic framework materials as chemical sensors. Chem. Rev. 2012, 112(2), 1105-1125. Kumar, R. S.; Kumar, S. S.; Kulandainathan, M. A. Efficient electrosynthesis of highly active Cu3(BTC)2-MOF and its catalytic application to chemical reduction. Microporous Mesoporous Mater. 2013, 168, 57-64.


Li, M.; Dinca, M. Reductive electrosynthesis of crystalline metal–organic frameworks. J. Am. Chem. Soc. 2011, 133(33), 12926-12929. Li, Y.; Huangfu, C.; Du, H.; Liu, W.; Li, Y.; Ye, J. Electrochemical behavior of metal–organic framework MIL-101 modified carbon paste electrode: An excellent candidate for electroanalysis. J. Electroanal. Chem. 2013, 709, 65-69.. Lin, Z.; Slawin, A. M.; Morris, R. E. Chiral induction in the ionothermal synthesis of a 3-D coordination polymer. J. Am. Chem. Soc. 2007, 129(16), 4880-4881. Liu, J.; Chen, L.; Cui, H.; Zhang, J.; Zhang, L.; Su, C. Y. Applications of metal–organic frameworks in heterogeneous supramolecular catalysis. Chem. Soc. Rev. 2014, 43(16), 60116061. Lu, G.; Hupp, J. T. Metal− organic frameworks as sensors: A ZIF-8 based Fabry− Pérot device as a selective sensor for chemical vapors and gases. J. Am. Chem. Soc. 2010, 132(23), 78327833.

22

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Martinez Joaristi, A.; Juan-Alca iz, J.; erra-Crespo, P.; Kapteijn F.; Gascon J. Electrochemical synthesis of some archetypical Zn2+, Cu2+, and Al3+ metal organic frameworks. Cryst. Growth Des. 2012, 12(7), 3489-3498. Morozan, A.; Jaouen, F. Metal organic frameworks for electrochemical applications. Energy Environ. Sci. 2012, 5(11), 9269–9290.


Mueller, U.; Schubert, M.; Teich, F.; Puetter, H.; Schierle-Arndt, K.; Pastré, J. Metal–organic frameworks—prospective industrial applications. J. Mater. Chem. 2006, 16(7), 626. Park, Y. K.; Choi, S. B.; Nam, H. J.; Jung, D. Y.; Ahn, H. C.; Choi, K.; Furukawa, H.; Kim, J. Catalytic nickel nanoparticles embedded in a mesoporous metal–organic framework. Chem. Commun. 2010, 46(18) 3086-3088. Parnham, E. R.; Morris, R. E. Ionothermal synthesis of zeolites, metal–organic frameworks, and inorganic–organic hybrids. Acc. Chem. Res. 2007, 40(10), 1005-1013. Phan, A.; Doonan, C. J.; Uribe-Romo, F. J.; Knobler, C. B.; O’keeffe, M.; Yaghi, O. M. Synthesis, structure, and carbon dioxide capture properties of zeolitic imidazolate frameworks. Acc. Chem. Res. 2010, 43(1), 58-67. Schlesinger, M.; Schulze, S.; Hietschold, M.; Mehring, M. Evaluation of synthetic methods for microporous metal–organic frameworks exemplified by the competitive formation of [Cu2(btc)3(H2O)3] and [Cu2(btc)(OH)(H2O)]. Microporous Mesoporous Mater. 2010, 132(1-2), 121-127.

23

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Senthil Kumar, R.; Senthil Kumar, S.; Anbu Kulandainathan, M. Highly selective electrochemical reduction of carbon dioxide using Cu based metal organic framework as an electrocatalyst. Electrochem. Commun. 2012, 25, 70-73. Shah, M.; McCarthy, M. C.; Sachdeva, S.; Lee, A. K.; Jeong, H. K. Current status of metal– organic framework membranes for gas separations: promises and challenges. Ind. Eng. Chem.


Res. 2012, 51(5), 2179-2199. Solla-Gullón, J.; Vidal-Iglesias, F. J.; Feliu, J. M. Shape dependent electrocatalysis. Annu. Rep. Sect. C: Phys. Chem. 2011, 107, 263. Stock, N.; Biswas, S. Synthesis of metal-organic frameworks (MOFs): routes to various MOF topologies, morphologies, and composites. Chem. Rev. 2011,112(2), 933-969. Suh, M. P.; Park, H. J.; Prasad, T. K.; Lim, D. W. Hydrogen storage in metal–organic frameworks. Chem. Rev. 2011, 112(2), 782-835. Sumida, K.; Rogow, D. L.; Mason, J. A.; McDonald, T. M.; Bloch, E. D.; Herm, Z. R.; Bae, T. H.; Long, J. R. Carbon dioxide capture in metal–organic frameworks. Chem. Rev. 2011, 112(2), 724-781. Tahmasian, A.; Morsali, A.; Joo, S. W. Sonochemical syntheses of a one-dimensional Mg (II) metal-organic framework: a new precursor for preparation of MgO one-dimensional nanostructure. J. Nano Mat. 2013, 2013(2514103), 10.

24

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Tan, K.; Nijem, N.; Canepa, P.; Gong, Q.; Li, J.; Thonhauser, T.; Chabal, Y. J. Stability and hydrolyzation of metal organic frameworks with paddle-wheel SBUs upon hydration. Chem. Mater. 2012, 24(16), 3153-3167. Turner, S.; Lebedev, O. I.;

chr der, F.; Esken, D.; Fischer R. A.; Tendeloo G. V. Direct

imaging of loaded metal− organic framework materials (Metal@ MOF-5). Chem. Mater. 2008,


20(17), 5622-5627. Wang, H.; Yin, F.; Li, G.; Chen, B.; Wang Z. Preparation, characterization and bifunctional catalytic properties of MOF (Fe/Co) catalyst for oxygen reduction/evolution reactions in alkaline electrolyte. Int. J. Hydrogen Energy. 2014, 39(28), 16179–16186. Wang, Y.; Ge, H.; Wu, Y.; Ye, G.; Chen, H.; Hu, X. Construction of an electrochemical sensor based on amino-functionalized metal-organic frameworks for differential pulse anodic stripping voltammetric determination of lead. Talanta. 2014, 129, 100-105. Wang, Y.; Wu, Y.; Xie, J.; Hu, X. Metal–organic framework modified carbon paste electrode for lead sensor. Sens. Actuators, B. Chem. 2013, 177, 1161-1166. Wen, L. L.; Wang, F.; Leng, X. K.; Wang, C. G.; Wang, L. Y.; Gong, J. M.; Li D. F. Efficient detection of organophosphate pesticide based on a metal−organic framework derived from biphenyltetracarboxylic acid. Cryst. Growth Des. 2010, 10(7), 2835-2838. Wu, X.; Bao, Z.; Yuan, B.; Wang, J.; Sun, Y.; Luo, H.; Deng S. Microwave synthesis and characterization of MOF-74 (M= Ni, Mg) for gas separation. Microporous Mesoporous Mater. 2013, 180, 114-122.

25

ACCEPTED MANUSCRIPT

ACCEPTED MANUSCRIPT Wu, Z. F.; Hu, B.; Feng, M. L.; Huang, X. Y.; Zhao, Y. B. Ionothermal synthesis and crystal structure of a magnesium metal-organic framework. Inorg. Chem. Commun. 2011,14(7), 11321135. Xu, Q.; Wang, Y.; Jin, G.; Jin, D.; Li, K.; Mao, A.; Hu X. Photooxidation assisted sensitive detection of trace Mn2+ in tea by NH2-MIL-125 (Ti) modified carbon paste electrode. Sens.


Actuators, B. Chem. 2014, 201, 274-280. Yaghi, O. M.; Li, H. Hydrothermal synthesis of a metal-organic framework containing large rectangular channels. J. Am. Chem. Soc. 1995, 117, 10401. Yang, H.; Du, H.; Zhang, L.; Liang, Z.; Li, W. Electrosynthesis and electrochemical mechanism of Zn-based metal-organic frameworks. Int. J. Electrochem. Sci. 2015, 10, 1420-1433. Yang, H.; Orefuwa, S.; Goudy, A. Study of mechanochemical synthesis in the formation of the metal–organic framework Cu3(BTC)2 for hydrogen storage. Microporous Mesoporous Mater. 2011, 143(1), 37-45. Yang, L.; Kinoshita, S.; Yamada, T.; Kanda, S.; Kitagawa, H.; Tokunaga, M.; Ishimoto, T.; Ogura, T.; Nagumo, R.; Miyamoto, A. A metal–organic framework as an electrocatalyst for ethanol oxidation. Angew. Chem. 2010, 122(31), 5476-5479. Zhan, W. W.; Kuang, Q.; Zhou, J. Z.; Kong, X. J.; Xie, Z. X.; Zheng L. S. Semiconductor@ metal–organic framework core–shell heterostructures: A case of ZnO@ ZIF-8 nanorods with selective photoelectrochemical response. J. Am. Chem. Soc. 2013, 135(5), 1926-1933.

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ACCEPTED MANUSCRIPT Zhang, C.; Wang, M.; Liu, L.; Yang, X.; Xu, X. Electrochemical investigation of a new Cu-MOF and its electrocatalytic activity towards H2O2 oxidation in alkaline solution. Electrochem. Commun. 2013, 33, 131-134. Zhang, Y.; Bo, X.; Nsabimana, A.; Han, C.; Li, M.; Guo, L. Electrocatalytically active cobaltbased metal–organic framework with incorporated macroporous carbon composite for


electrochemical applications. J. Mater. Chem. A. 2015, 3(2), 732-738. Zhang, Y.; Nsabimana, A.; Zhu, L.; Bo, X.; Han, C.; Li, M.; Guo L. Metal organic frameworks/macroporous carbon composites with enhanced stability properties and good electrocatalytic ability for ascorbic acid and hemoglobin. Talanta 2014, 129, 55-62. Zheng, B.; Yun, R.; Bai, J.; Lu, Z.; Du, L.; Li, Y. Expanded porous MOF-505 analogue exhibiting large hydrogen storage capacity and selective carbon dioxide adsorption. Inorg. Chem. 2013, 52(6), 2823-2829. Zhou, E.; Zhang, Y.; Li, Y.; He, X. Cu(II)‐based MOF immobilized on multiwalled carbon nanotubes: Synthesis and application for nonenzymatic detection of hydrogen peroxide with high sensitivity. Electroanalysis. 2014, 26(11), 2526-2533.

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ACCEPTED MANUSCRIPT Table 1: Selected examples of metal–organic frameworks (MOFs) for electrochemical sensing MOF formula Cu-MOF ZnO4(BDC)3


Cu(adp)(BIB)(H2O)]n MIL-101 (Cr3X(H2O)2O(bdc)3 MIL-101 (Cr3X(H2O)2O(bdc)3 [Cd(2,2´,4,4´bptcH2)]n

Mechanism of detection electrocatalytic oxidation

Analyte

Linear range (μmol L-1) Ref.

L-cysteine

0.02-300

electrochemical oxidation electrocatalytic oxidation electrocatalytic oxidation electrocatalytic oxidation Electrooxidation

Lead

0.01-1

Hosseini et al., 2013 Wang et al., 2013

H2O2

0.1-2.75

Zhang et al., 2013

dopamine

5–250

Li et al., 2013

uric acid

30–200

Li et al., 2013

methyle parathion Hydrazine

0.01- 0.5*

Wen et al., 2010

0.04–500

Lead

0.01-0.5

Hosseini et al., 2013 Wang et al., 2014

ascorbic acid

10 - 2360

Zhang et al., 2014

Hemoglobin

0.1 - 1.3

Zhang et al., 2014

nitrite and iodate ascorbic acid

-

Fernandes et al. 2014 Fernandes et al., 2014 Zhou et al., 2014

Cu-MOF

electrocatalytic oxidation

NH2–Cu3(BTC)2

electrochemical oxidation electrocatalytic oxidation electrocatalytic reduction electrocatalytic reduction

Cu-MOFs Cu-MOFs SiW11Fe@MIL-101 SiW11Fe@MIL-101


Cu(II)-based MOF (Cu-bipy-BTC)

electrocatalytic reduction

Co-MOF [Co2(4ptz)2-(bpp) (N3)2]n


Co-MOF [Co2(4ptz)2-(bpp) (N3)2]n

electrocatalytic reduction

hydrogen peroxide Hydrazine

-

3–70 and 70– 30000 5-630 and 6305400 Nitrobenzene 0.5–15 and 15235

Zhang et al., 2015 Zhang et al., 2015

*

μg mL-1

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Fig. 1. The exponential increase in the number of MOF publications. Data was obtained from Scopus-Analyse using the search input: metal-organic framework.

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Fig. 2. Schematic illustration of the structure of the electrolytic cell. Reprinted from (Jia et al., 2013) with permission from Elsevier Publications.

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Fig. 3. Reaction scheme of the electrosynthesis of DMC over the Cu (II)-based MOF. Reprinted from (Jia et al., 2013) with permission from Elsevier Publications.

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Fig. 4. Schematic of the chemical structures of (a) Reduced GO (r-GO), (b) G-dye, (c) TCPP, (d) (Fe−P)n MOF, (e) (G-dye-FeP)n MOF, and (f) Magnified view of layers inside the framework of (G-dye-FeP)n MOF.Reprinted from (Jahan et al., 2012) with permission from ACS Publications.

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Fig. 5. Differential pulse anodic stripping voltammograms of lead (a) with an unmodified CPE in absence of lead; (b) with an unmodified CPE and 1×10 −6 mol L−1 of lead and (c) with a CPE modified with MOF-5 and 1×10−6 mol L−1 of lead. Inset: SEM image of the fabricated MOF-5 modified CPE.Reprinted from (Wang et al., 2013) with permission from Elsevier Publications.

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Fig. 6. Schematic of detection of MP on MOF/GCE by SWV. Reprinted from (Wen et al., 2010) with permission from ACS Publications.

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Fig. 7. CVs of SiW11Fe@MIL-101 immobilized on a PG electrode in pH 2.5 H2SO4/Na2SO4 buffer solution at different scan rates from 0.04 to 0.5 Vs-1. Reprinted from (Fernandes et al., 2014) with permission from Wiley Publications.

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Fig. 8. The photocurrent generation mechanism of a MOF-5 modified GCE. Reprinted from (Hou, Peng et al. 2012) with permission from the Royal Society of Chemistry Publications.

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