Analysis of biomolecule detection with optofluidic ring resonator sensors

TLDR

The study evaluates the biomolecule detection capability of liquid core optical ring resonators as label‑free biosensors. The authors derive a linear relation between bulk refractive index sensitivity and surface‑deposition response, then test LCORRs with bovine serum albumin across different sensitivities. Experimental results agree with theory and show LCORR can detect BSA below 10 pM with a sub‑picogram per mm² mass detection limit.

Abstract

We theoretically and experimentally analyze the biomolecule detection capability of the liquid core optical ring resonator (LCORR) as a label-free bio/chemical sensor. We first establish a simple and general linear relationship between the LCORR's bulk refractive index sensitivity (BRIS) and its response to molecule deposition onto the surface, which enables us to easily characterize the LCORR sensing performance. Then, biosensing experiments are performed with bovine serum albumin (BSA) and LCORRs of various BRISs. The experimental results are in good agreement with the theoretical prediction. Further analysis shows that the LCORR is capable of detecting BSA below 10 pM with sub-picogram/mm2 mass detection limit.