Monolithic Electronic–Biophotonic System-on-Chip for Label-Free Real-Time

Abstract

Label-free miniaturized optical sensors can have a tremendous impact on highly sensitive and scalable point- of-care (PoC) diagnostics by monitoring real-time molecular interactions without any labels. However, current biophotonic platforms are limited by complex optical and external readout equipment, precluding their use in a PoC setting. In this work, we address this challenge by developing a first-of-its-kind fully integrated electronic–photonic label-free molecular sensor utilizing microring resonators (MRRs) co-integrated with on- chip electronics in a high-volume advanced electronic process. In particular, we present an arrayed electronic–photonic system- on-chip (EPSoC) in GlobalFoundries (GF) 45-nm RFSOI with 60 5-µm radius MRRs connected to on-chip receivers, approach- ing an idealized limit of detection (LoD) equivalent to a single 140-nm viral particle. To further enhance the LoD, we propose a dual-ring phase-based sensing architecture, boosting the system’s sensitivity by 3.7× compared to our previously reported intensity- based single MRR scheme. An integrated heater embedded in the design of the ring and an on-chip controller locks the ring’s Manuscript received 12 October 2023; revised 4 January 2024 and 15 February 2024; accepted 18 March 2024. Date of publication 9 April 2024; date of current version 27 August 2024. This article was approved by Associate Editor Nick Helleputte. This work was supported in part by the NIH/National Heart, Lung, and Blood Instit