Compact plasmonic optical biosensors based on nanostructured gradient index lenses integrated into microfluidic cells
| Autor: | Monika Fleischer, Andreas Horrer, Dieter P. Kern, Günter Gauglitz, Kathrin Freudenberger, Jonas Haas |
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| Rok vydání: | 2017 |
| Předmět: |
Materials science
Microfluidics Physics::Optics Biosensing Techniques 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention Optics law Miniaturization Testosterone General Materials Science Surface plasmon resonance Plasmon Immunoassay business.industry Optical Imaging Surface Plasmon Resonance 021001 nanoscience & nanotechnology Nanostructures 0104 chemical sciences Lens (optics) Gradient-index optics Gold 0210 nano-technology business Biosensor Refractive index |
| Zdroj: | Nanoscale. 9:17378-17386 |
| ISSN: | 2040-3372 2040-3364 |
| DOI: | 10.1039/c7nr04097k |
| Popis: | We report on a compact and cost-effective integrated label-free biosensor configuration which is based on the refractive index sensitivity of the localized surface plasmon resonance (LSPR) of gold nanostructures. Aiming for compactification and miniaturization of the sensor, arrays of nanodiscs were fabricated on the planar surface of a gradient index (GRIN) lens, which acts as a substrate as well as an imaging objective for the light scattered by the gold structures. Integration of the lens into a microfluidic flow cell enabled the controlled exchange of liquid media at the sensor surface. The light scattered by the nanostructures was investigated spatially and spectrally resolved making use of the imaging properties of the GRIN lens. Dynamic spectral analysis during refractive index changes was conducted, revealing high sensitivities of up to 372 nm per refractive index unit for the shift of the LSPR. Biosensing capabilities were demonstrated by the detection of binding of an analyte by means of a testosterone-immunoassay. |
| Databáze: | OpenAIRE |
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