Surface-Modified Micro-Ring-Resonator Sensors for HMGB1 Detection on a Chip-Scale Platform

High mobility group box 1 (HMGB1) is considered a pivotal mediator and biomarker in inflammatory diseases, garnering increasing attention for precise detection. Silicon on insulator (SOI) integrated waveguide biosensors have the advantages of high sensitivity, easy functionalization, and compatibility with CMOS technology, promising enhanced sensing of HMGB1. Here, we propose a chip-scale, cost-effective HMGB1 sensor device based on a micro-ring resonator (MRR), which is surface functionalized by a chemical bonding method. This sensor enables quantitative determination of HMGB1 concentration, with a sensitivity reaching 1.75 pm/nM and a detection limit as low as 0.13 μg/mL (4.99 nM). The HMGB1 concentration was accurately determined in a mixed solution environment of unknown concentration with an average error of only 5.4%. This study demonstrates the excellent performance of a surface-modified HMGB1 antibody MRR sensor in sensing HMGB1 concentration.