Chip-Based Integrated Filterless Multi-Wavelength Optoelectronic Bio-Chemical Sensors

Abstract

High-sensitivity (parts-per-billion) optical sensors based on fluorescence, absorption, and scattering can be employed not only for detection of various analytes, but also to determine the concentration, size, temperature, pressure, and flow of the medium. Even modern compact portable systems based on solid-state lasers. Light emitting diodes (LEDs), and photodiodes (PD) use traditional optic elements, such as lenses and glass or interference optical filters to make the spectral bands of both light sources and photodetectors selective in order to characterize specific parameters. In this work we demonstrated integration of multi-spectral III nitride based wavelength-selective LED and PD chips on a single miniature substrate, which will allow for avoiding optical filters and waveguides. The multifunctional capabilities of such sensor are provided by the multi-band LED emission and detection in a wide wavelength range from near UV to near IR. Such capabilities will be further improved in the proposed sensors by using a surface enhancement effect (SEE) based on employment of by metal nanostructures in the analyte vicinity