Bioinspired Plasmonic Nanosensor for on-Site Antimicrobial Susceptibility Testing in Urine Samples

Abstract

Delayed use of appropriate antibiotics for superbugs, particularly for extended-spectrum β-lactamase (ESBL)-producing <i>Escherichia coli</i> (<i>E. coli</i>) and <i>Klebsiella pneumoniae</i> (<i>K. pn</i>), has caused extensive morbidity and mortality worldwide. Therefore, rapid and on-site antimicrobial susceptibility testing (AST) is urgently required. Unfortunately, currently, no phenotypic AST can realize a sample-to-answer result within 2 h directly from a clinical sample and without using laboratory equipment or customized devices. Inspired by observing that <i>E. coli</i> and <i>K. pn</i> can rapidly catalyze H₂O₂, we developed a plasmonic nanosensor that responds to the proliferation of bacteria for realizing rapid AST. The results can be determined with the naked eye, digitized using a smartphone, and validated using ultraviolet-visible spectrometry. Our assay achieved superb area under the curves of 0.9752 and 1 in a receiver operating characteristic analysis directly obtained from uncultured clinical urine samples infected by <i>E. coli</i> and <i>K. pn</i>, respectively. The entire process from sample collection to analysis takes 100 min for <i>E. coli</i> and 85 min for <i>K. pn</i> detection. Our platform provides a practical approach for performing on-site AST in clinics to improve the survival of patients. It releases the burden of superbugs and avoids the abuse of antibiotics.