Chip-size wavelength detectors and their use in biosensing
We will describe compact wavelength detectors and spectrometers that are capable of resolving wavelength changes of less than 1 pm over a broad spectral range. These devices have been used to interrogate optical sensors (e.g., fiber Bragg sensors and two-dimensional photonic crystals) and to conceptualize various types of biosensors. Our optical subsystem can provide both an "event trigger" and "identification into classes" of bio-molecules and chemicals in water. The detection platform is designed to record the auto-fluorescence properties of analytes in water "on the flow" and can be assembled into an extremely compact subsystem. Our approach combines enhanced light-target interaction and chip-size wavelength detectors with a method for spectral characterization of moving analytes. Unlike most other approaches for detecting and identifying analytes, ours does not require concentrating or immobilizing suspect particles for interrogation. Rather, it takes advantage of the general necessity to detect such particles in real time as they are moving. Our concept permits warning (triggering) of suspicious particles and class identification simultaneously. This information can be used to initiate further processing in a second stage, such as identification, removal, disinfection, capturing or sorting of agents. To highlight some key features, our CB detector subsystem yields detailed spectral data (essential for the differentiation of agents in mixtures), can be extremely compact, does not rely on PMTs, is extendable with other electrical or optical characterization modules, and can be readily integrated into a complete water treatment system.
Kiesel, P. ; Schmidt, O. ; Bassler, M. ; Johnson, N. M. Chip-size wavelength detectors and their use in biosensing. Invited seminar talk at Bosch AG, Zentrale Forschung und Vorausentwicklung, Stuttgart, Germany.