Integrated photonic structures for parallel fluorescence and refractive index biosensing

Abstract

We present a multi-modality optical sensing platform employing integrated Vertical Cavity Surface Emitting Lasers (VCSELs), photodetectors, and filters suitable for portable, real-time analyte detection in aqueous environments. Fluorescence and refractive index sensors designed to utilize visible and near-infrared VCSELs for low background absorption from analyte delivery fluids are described. We demonstrate in vitro fluorescence sensing of Cy5.5 dye with a detection sensitivity of 5 nM and photonic crystal slab refractive index sensing with tunable GaAs-based 670 nm VCSELs. This compact, parallel sensor architecture enables multiplexed, cost-effective on-chip biosensing.

Optical sensors: from micro to nano and beyond

“…A plethora of novel applications in biology, chemistry, medicine, and defense would be possible if we could accurately detect, track, and identify targets in highly cluttered, dynamic environments. 1 Compact, multimodal sensing capable of detecting multiple characteristics of the electromagnetic radiation or optical materials, such as intensity, phase, wavelength, polarization, or refractive index (see Figure 1), offers a potential way to do this. There has been tremendous progress in the field of optical sensors over the last decade, but despite this, there are still challenging issues that need to be solved.…”