Amikacin- and AuNP-mediated colorimetric biosensor for the rapid and sensitive detection of bacteria

Abstract

Bacterial contamination has been recognized as a major public health concern worldwide, leading to putrefaction of food and endanger human health. In this study, we proposed a novel biosensing strategy for bacterial sensing based on modified gold nanoparticles (AuNPs) combined with amikacin as the molecular recognition element. Amikacin, an antibacterial drug, acts not only as a specific binder for bacteria but also as an aggregator for AuNPs. Without bacteria, amikacin combined with AuNPs, once target bacteria existed, they bound to bacteria that rendered the AuNPs free, providing a colorimetric readout of the binding event. The biosensor shows a good linear correlation with the concentration of bacteria ranging from 10 to 106 CFU/mL, with a limit of detection at 104 CFU/mL and 2.9 log CFU/mL by naked eyes and simple spectroscopic analysis of bacterial, respectively. Furthermore, the detection time was within 10 min without any expensive reagents or complex instruments. Briefly, we proposed a novel, easy, and rapid method, and it could be promising for the on-site detection of bacterial in food processing plant.