Photonic integrated circuits for rapid sensing of biomolecules (Conference Presentation)

Most immunoassays today use end-point detection methods that require several labour-intensive wash steps before each measurement. Recent advances have led to the development of several surface-sensitive transduction methodologies with evanescent excitation or evanescent collection being used. However, we have not come across transducers that use both evanescent excitation and collection to maximize surface sensitivity. In this work, we present a novel waveguide transducer that uses the evanescent field to excite surface bound fluorophores and collects only the exponentially decaying supercritical angle fluorescence emission from them. In addition, the use of photonic integrated circuits has made it possible to integrate structures that can filter out excitation light and improve the sensor’s dynamic range.