J. Biophotonics 5, No. 7–8, 599–600 (2012) / DOI 10.1002/jbio.201200509
Journal of
BIOPHOTONICS Editorial Biophotonics on a chip The concept to integrate the sensing of biological parameters on-chip has been commercialized for a number of applications [1]. While a number of biosensors are based on measuring electrical, magnetic, or mechanical signals [2], there is a growing field applying optical and photonic sensing in miniaturized systems. Classical biophotonic sensing uses the detection either of photons from fluorescence markers, or of the change of refractive indices upon a biological binding event to transducer elements. Alternative approaches apply highly integrated imaging on-chip either as pattern recognition or as advanced microscopy. This topical issue is dedicated to biophotonic lab-on-a-chip devices for diagnostics. It aims for providing a representative and comprehensive overview on the broad range of current biophotonics on-chip, spanning the full range from chip fabrication to applications in biomedical sensing and related fields. To this end, a balanced mix of original research work and reviews for broader perspective is presented. The issue starts with an overview on the integration of photonic crystal structures on-chip by the group of M. Gerken [pp. 601–616]. B. Cunningham and co-workers provide a comprehensive review on the potential of surface-based fluorescent assays. Recent developments allow for inexpensive fabrication of photonic crystal surfaces over substantial surface areas and in low autofluorescence materials, opening the market for disposable devices [pp. 617–628]. Another approach showing the capabilities of resonant structures is presented in an original work by M. A. Santiago-Cordoba and co-workers. They present ultrasensitive detection of a protein by optical trapping at the site of plasmonic field enhancement on the surface of a whispering-gallery mode microcavity [pp. 629–638]. Integrating microscopy on-chip for medical and biological applications is discussed in a re-
view by G. Zheng. He analyzes illumination design, sample manipulation and substrate/imager modifications required for different configurations of chip-scale microscopical imaging. Future developments targeting high throughput sample manipulation are discussed in his article [pp. 639–649]. Microscopical imaging is used in applications for on-chip non-invasive assisted reproductive technology discussed in the review of the group S. Takayama [pp. 650–660]. Their article illustrates the power of biophotonics in assessing sperm cells, egg, and embryo cells to continuously improve the outcome of in-vitro fertilization procedures using low-volume microchip environments. The high potential of high-accuracy diagnosis for exploring cell properties on chip is further discussed using the example of algae detection and classification by the group of Y. Bellouard [pp. 661–672]. This contribution illustrates that on-chip diagnostics encompasses not only biomedicine, but extends to a much broader range of applications involving liquid environments such as water quality control. On-chip imaging is extended to single DNA molecule sequence mapping by integrating nanofluidics to form complete systems. Current research activities are described in detail in a review by R. Marie and A. Kristensen [pp. 673–686]. The issue concludes with two contributions reviewing recent work on fabrication technologies for biophotonic lab-on-a-chip devices. S. M. Eaton and co-workers showcase femtosecond laser microstructuring in polymers, one example for a promising technique to create topologies, e.g. surface microchannels and diffractive optics or refractive index modification for buried optical waveguides and micro-optics [pp. 687–702]. Y. Zhao and co-workers complete this topical issue by reviewing recent progress in incorporating optical signal processing such as spectral filters with liquid-core optical waveguides. They
# 2012 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Journal of
BIOPHOTONICS 600
provide an example for the growing integration of integrated optics with microfluidics to create optofluidic devices that can form the basis of fully integrated diagnostic instruments [pp. 703– 711]. Timo Mappes Institute of Microstructure Technology Karlsruhe Institute of Technology (KIT) Karlsruhe, Germany Holger Schmidt School of Engineering and W. M. Keck Center for Nanoscale Optofluidics University of California, Santa Cruz, CA, USA
Timo Mappes earned a Ph.D. in mechanical engineering with great distinction from Karlsruhe Institute of Technology (KIT), Germany in 2006. Since 2007, he is heading an interdisciplinary group on biophotonic sensors. For half a year he was working as visiting professor at Technical University of Denmark (DTU) in 2010. He defended his Habilitation at KIT in 2011. His research focuses on realizing and process engineering highly integrated optical lab-on-a-chip systems out of polymers. He integrates on-chip lasers based on both, solid-state and liquid core (optofluidics). With his group he introduced a new type of active microresonator for the use as label free sensor.
# 2012 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Editorial
Holger Schmidt received his Ph.D. degree in electrical and computer engineering from the University of California, Santa Barbara. After serving as a Postdoctoral Fellow at M.I.T., he joined the University of California, Santa Cruz, in 2001, where he is professor of electrical engineering and Director of the W. M. Keck Center for Nanoscale Optofluidics. His research interests include optofluidic devices, single-photon nonlinearities, and nano-magneto-optics. He received a National Science Foundation CAREER Award in 2002 and a Keck Futures Nanotechnology Award in 2005.
References [1] D. Janasek, J. Franzke, and A. Manz, Nature 442, 374 (2006). [2] H. Hunt and A. M. Armani, Nanoscale 2, 1544 (2010).
www.biophotonics-journal.org
Journal of
BIOPHOTONICS Editorial Biophotonics on a chip The concept to integrate the sensing of biological parameters on-chip has been commercialized for a number of applications [1]. While a number of biosensors are based on measuring electrical, magnetic, or mechanical signals [2], there is a growing field applying optical and photonic sensing in miniaturized systems. Classical biophotonic sensing uses the detection either of photons from fluorescence markers, or of the change of refractive indices upon a biological binding event to transducer elements. Alternative approaches apply highly integrated imaging on-chip either as pattern recognition or as advanced microscopy. This topical issue is dedicated to biophotonic lab-on-a-chip devices for diagnostics. It aims for providing a representative and comprehensive overview on the broad range of current biophotonics on-chip, spanning the full range from chip fabrication to applications in biomedical sensing and related fields. To this end, a balanced mix of original research work and reviews for broader perspective is presented. The issue starts with an overview on the integration of photonic crystal structures on-chip by the group of M. Gerken [pp. 601–616]. B. Cunningham and co-workers provide a comprehensive review on the potential of surface-based fluorescent assays. Recent developments allow for inexpensive fabrication of photonic crystal surfaces over substantial surface areas and in low autofluorescence materials, opening the market for disposable devices [pp. 617–628]. Another approach showing the capabilities of resonant structures is presented in an original work by M. A. Santiago-Cordoba and co-workers. They present ultrasensitive detection of a protein by optical trapping at the site of plasmonic field enhancement on the surface of a whispering-gallery mode microcavity [pp. 629–638]. Integrating microscopy on-chip for medical and biological applications is discussed in a re-
view by G. Zheng. He analyzes illumination design, sample manipulation and substrate/imager modifications required for different configurations of chip-scale microscopical imaging. Future developments targeting high throughput sample manipulation are discussed in his article [pp. 639–649]. Microscopical imaging is used in applications for on-chip non-invasive assisted reproductive technology discussed in the review of the group S. Takayama [pp. 650–660]. Their article illustrates the power of biophotonics in assessing sperm cells, egg, and embryo cells to continuously improve the outcome of in-vitro fertilization procedures using low-volume microchip environments. The high potential of high-accuracy diagnosis for exploring cell properties on chip is further discussed using the example of algae detection and classification by the group of Y. Bellouard [pp. 661–672]. This contribution illustrates that on-chip diagnostics encompasses not only biomedicine, but extends to a much broader range of applications involving liquid environments such as water quality control. On-chip imaging is extended to single DNA molecule sequence mapping by integrating nanofluidics to form complete systems. Current research activities are described in detail in a review by R. Marie and A. Kristensen [pp. 673–686]. The issue concludes with two contributions reviewing recent work on fabrication technologies for biophotonic lab-on-a-chip devices. S. M. Eaton and co-workers showcase femtosecond laser microstructuring in polymers, one example for a promising technique to create topologies, e.g. surface microchannels and diffractive optics or refractive index modification for buried optical waveguides and micro-optics [pp. 687–702]. Y. Zhao and co-workers complete this topical issue by reviewing recent progress in incorporating optical signal processing such as spectral filters with liquid-core optical waveguides. They
# 2012 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Journal of
BIOPHOTONICS 600
provide an example for the growing integration of integrated optics with microfluidics to create optofluidic devices that can form the basis of fully integrated diagnostic instruments [pp. 703– 711]. Timo Mappes Institute of Microstructure Technology Karlsruhe Institute of Technology (KIT) Karlsruhe, Germany Holger Schmidt School of Engineering and W. M. Keck Center for Nanoscale Optofluidics University of California, Santa Cruz, CA, USA
Timo Mappes earned a Ph.D. in mechanical engineering with great distinction from Karlsruhe Institute of Technology (KIT), Germany in 2006. Since 2007, he is heading an interdisciplinary group on biophotonic sensors. For half a year he was working as visiting professor at Technical University of Denmark (DTU) in 2010. He defended his Habilitation at KIT in 2011. His research focuses on realizing and process engineering highly integrated optical lab-on-a-chip systems out of polymers. He integrates on-chip lasers based on both, solid-state and liquid core (optofluidics). With his group he introduced a new type of active microresonator for the use as label free sensor.
# 2012 by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Editorial
Holger Schmidt received his Ph.D. degree in electrical and computer engineering from the University of California, Santa Barbara. After serving as a Postdoctoral Fellow at M.I.T., he joined the University of California, Santa Cruz, in 2001, where he is professor of electrical engineering and Director of the W. M. Keck Center for Nanoscale Optofluidics. His research interests include optofluidic devices, single-photon nonlinearities, and nano-magneto-optics. He received a National Science Foundation CAREER Award in 2002 and a Keck Futures Nanotechnology Award in 2005.
References [1] D. Janasek, J. Franzke, and A. Manz, Nature 442, 374 (2006). [2] H. Hunt and A. M. Armani, Nanoscale 2, 1544 (2010).
www.biophotonics-journal.org
