Innovative electrochemiluminescence biosensing platform with biocompatible interface for monitoring hydrogen peroxide metabolism and antibiotic stress response in Escherichia coli

Background Escherichia coli ( E. coli ) is a model microorganism extensively used in microbial research due to its well-characterized physiology and genetic tractability. Monitoring its physiological indicators, such as metabolic activity and stress responses, is essential for understanding microbial life processes. However, existing methods often lack sensitivity, rapidity, and biocompatibility. This study addresses these limitations by combining electrochemiluminescence (ECL) biosensing with a biocompatible interface, to enable precise and efficient monitoring of E. coli 's physiological state. Results This study presents a novel ECL biosensor that leverages the biocompatibility of bovine serum albumin (BSA) with E. coli . The biosensor employs horseradish peroxidase (HRP) and 4-chloro-1-naphthol (4-CN) to induce a precipitation reaction that quenches the ECL signal of CdS–K 2 S 2 O 4 , enabling the sensitive detection of endogenous hydrogen peroxide (H 2 O 2 ) produced by E. coli . The sensor exhibits excellent linearity, stability, and reproducibility, with a detection limit of 54 nM for H 2 O 2 . Additionally, the biosensor effectively distinguishes between antibiotic-resistant and sensitive strains of E. coli , demonstrating its potential for comprehensive physiological assessment. Significance This innovative ECL biosensor represents a significant advancement in microbial monitoring, combining high sensitivity, rapidity, and biocompatibility, offering a powerful tool for comprehensive physiological monitoring in bioanalytical sciences. Its potential applications in biotechnology, food industry, and drug research highlight its practical relevance.