Efficient capture and ultra-sensitive detection of drug-resistant bacteria ESBL-E. coli based on self-assembled Au NPs and MXene-Au SERS platform

Drug-resistant bacteria is highly infectious and has been appearing in food in recent years threatening human health. Therefore, effective detection of drug-resistant bacteria is crucial. In this paper, an interference-free surface-enhanced Raman scattering (SERS) platform was developed for the detection of extended-spectrum β-lactamase E. coil (ESBL-E. coil). 4-mercaptomethylboronic acid (4-MPBA) was used as a capture molecule for drug-resistant bacteria, and self-assembled gold nanoparticles (Au NPs) were utilized to develop a high-performance SERS analytical platform for the detection of drug-resistant bacteria. Meanwhile, in order to obtain a lower detection limit and higher precision, Ti3C2Tx, modified with 4-mercaptobenzonitrile (4-MBN) and Au NPs, was used for signal enhancement and indirect detection. The SERS platform detected signals from the Raman silent region, where there was no background signal from biological sources, eliminating the interference, a detection limit was 10 CFU/mL, with a wide dynamic linear range from 10-108 CFU/mL. Meanwhile, the stability, homogeneity and reproducibility were excellent. The precise quantification capability of the SERS platform was validated by the detection of ESBL-E. coil in milk. Therefore, the method holds great promise for the development of a stable and sensitive SERS platform for the detection of drug-resistant bacteria.