Research Topics

PLASMON-ENHANCED FLUORESCENCE (PEF)

The coupling of fluorophores with surface plasmons on continuous metallic films or metallic nanoparticles can be exploited for amplification of fluorescence signal in assays for detection of molecular analytes. Plasmonic structures can be designed to enhanced the fluorescnce signal through combined effect of plasmon-enhanced excitation rate at the absorption wavelength of a dye, highly directional angular emission distribution, and improved quatum yield. Particularly, we focus on schemes that are compatible with compact / portable sensor devices and advanced multiplexing of sensing channels.

 

plasmon enhanced fluorescenc

 

external       M. Bauch, K. Toma, M. Toma, Q. Zhang, J. Dostalek, Surface plasmon-enhanced fluorescence biosensors: a review, Plasmonics (2014), in press. pdf

external       M. Bauch, J. Dostalek, Collective localized surface plasmon-enhanced fluorescence for high performance biosensors, Optics Express (2013) 21(17) pp 20470-20483. pdf

external       K. Toma, M. Vala, P. Adam, J. Homola, W. Knoll, J. Dostalek, Compact surface plasmon-enhanced fluorescence biochip, Optics Express (2013), 21(8), 10121-10132. pdf

external      K. Toma, E. Descrovi, M. Toma, M. Ballarini, P. Mandracci, F.Giorgis, A.Mateescu, U. Jonas, W. Knoll, J. Dostalek, Bloch Surface Wave-Enhanced Fluorescence Spectroscopy Biosensor, Biosensors and Bioelectronics (2013), 43, 108-114. pdf

external      M. Toma, K. Toma, P. Adam, J. Homola, W. Knoll, J. Dostalek, Surface plasmon-coupled emission on plasmonic Bragg gratings, Optics Express, (2012), 20(13), 14042. pdf

external        K.Toma, J. Dostalek, W. Knoll, Long-Range Surface Plasmon-Coupled Emission for Biosensor Applications, Optics Express (2011), Vol. 19, Iss. 12, pp. 11084–11089. pdf

external      J. Dostalek, W. Knoll, Biosensors based on surface plasmon-enhanced fluorescence spectroscopy, Biointerphases, (2008), Vol. 3, No.3, 12-22. pdf

external   J. Dostalek, A.Kasry, W. Knoll, Long range surface plasmons for observation of biomolecular binding events at metallic surfaces, Plasmonics (2007) 2, 97-106. pdf


DIRECT (LABEL-FREE) OPTICAL BIOSENSOR SCHEMES

In colaboration with Jonas group at University of Siegen, we conduct research on implementation of various polymers, particularly hydrogels, to plasmonic biosensors. For instance, these materials can be used in biointerfaces with large binding capacity due to their huge inner surface area, highly open structure and good anti-fouling properties. This research goes towards continuous monitoring based on immunoassays and molecular imprinted polymers (MIPs). Within this framework, hydrogel optical waveguide spectroscopy (HOWS) can be used in which the polymer layer serves simultanouesly as a binding matrix and a waveguide offering direct refractimetric detection with the figure of merit (FOM) as large as 800 RIU-1. Reseach on overcoming diffusion-limited mass transfer of analytes from a sample to the sensor suface is pursued.

 

Refractometric biosensors

 

external      Y. Wang, W. Knoll, J. Dostalek, Long Range Surface Plasmon Resonance Biosensor for Magnetic Nanoparticle-Enhanced Detection of Bacterial Pathogens, Analytical Chemistry, (2012), 84, 8345-8350. pdf

external       M. Toma, W. Knoll, J. Dostalek, Bragg-scattered surface plasmon microscopy, Plasmonics, (2012) 7(2), 293-299. pdf

external       Y.Wang, J. Dostalek, W. Knoll, Magnetic Nanoparticle-Enhanced Biosensor Based On Grating-Coupled Surface Plasmon Resonance, Analytical Chemistry (2011), 83, 6202–6207.pdf

external    Y. Wang, C.J. Huang, U. Jonas, T. Wei, J. Dostalek, W. Knoll, Biosensor based on Hydrogel Optical Waveguide Spectroscopy, Biosensors and Bioelectronics, (2010), 25, 1663-1668. pdf

external    A. Aulasevich, R.F. Roskamp, U. Jonas, B. Menges, J. Dostalek, W. Knoll, Optical waveguide spectroscopy for the investigation of protein-functionalized hydrogel films, Macromolecular Rapid Communications, (2009), 30, 872-877. pdf

external   J. Dostalek, R. F. Roskamp, W. Knoll, Coupled long range surface plasmons for the investigation of thin films and interfaces, Sensors and Actuators B, (2009), 139, 9-12.  pdf


BIOSENSOR APPLICATIONS

The research work in biosensor area aims to impact the fields of medical diagnostics and food control. In particular, new systems that can povide rapid, sensitive, and on site analysis of trace about of chemical and biological species are investigated. These include biosensors for detection of small molecules (such as estradiol, aflatoxin M1), medium size biomakers (prostate specific antigen, interleukin IL-6), and larger bacterial pathogens (E. coli O157:H7).

 

Biosensor applications

 

external       Q. Zhang, Y. Wang, A., Mateescu, K. Sergelen, A. Kibrom, U. Jonas, T. Wei, J. Dostalek, Biosensor Based on Hydrogel Optical Waveguide Spectroscopy for the Detection of 17β-Estradiol, Talanta, (2013), 104, 149-154. pdf

external       C.J. Huang, J. Dostalek, A. Sessitsch, W. Knoll, Long-Range Surface Plasmon-Enhanced Fluorescence Spectroscopy Biosensor for Ultrasensitive Detection of E. coli O157:H7, Analytical Chemistry (2011), 83 (3), 674–677. pdf

external    Y. Wang, Annette Brunsen, U. Jonas, J. Dostalek, W. Knoll, Prostate Specific Antigen Biosensor Based on Long Range Surface Plasmon-Enhanced Fluorescence Spectroscopy and Dextran Hydrogel Binding Matrix, Analytical Chemistry, (2009) 81, 23, 9625-9632. pdf

external    Y. Wang, J. Dostalek, W. Knoll, Long range surface plasmon-enhanced fluorescence spectroscopy for the detection of aflatoxin M1 in milk, Biosensors and Bioelectronics, (2009), 24, 2264-2267.  pdf