Enhanced Ratiometric Detection using a Buried Dual Junction Diode for Wearable Optofluidic Biosensing Application

摘要

We demonstrate a novel integrated silicon buried dual-junction (BDJ) photodiode-based device as a first step towards viable microscale integration of an optofluidic wearable biosensor for continuous monitoring of analytes within human interstitial fluid (ISF). Specifically, we show our BDJ photodetector is applicable for optical FRET-based ratiometric sensing of relevant fluorophores with 1µM sensitivity in a ~7 µL volume fluid cavity. We have also implemented and demonstrated the effectiveness of an optical filtering system to increase the sensitivity and the signal to background ratio of our photodetector. Given integration with an array of silicon hollow microneedles that we have previously designed and fabricated, and a FRET-based optical analyte sensor we have recently produced, we show that our system can operate within at the sample size and concentration required for wearable applications, thus effectively delivering the first results towards a truly integrated, wearable, optical biosensor.