Colorimetric sensor array for sensitive detection and identification of bacteria based on the etching of triangular silver nanoparticles regulated by Cl? at various?…
Abstract
A?colorimetric sensor array is?proposed for ultrasensitive detection and identification of bacteria by using Cl? at various concentrations as sensing elements and triangular silver nanoparticles (T-AgNPs) as a single sensing nanoprobe. T-AgNPs are easily etched by Cl?. However, in the presence of bacteria, the etching process will be hindered. Different bacteria have differential protective effects on T-AgNPs due to their interactions, resulting in different etching degrees of T-AgNPs by Cl?, and visual color changes. By adjusting the antagonistic action between bacteria protection on T-AgNPs and the etching by using Cl? at various concentrations, different?bacteria had their own color response patterns. Combined with linear discriminant analysis (LDA) and orthogonal partial least squares-discriminant analysis?(OPLS-DA), the bacteria could be identified. The?method was also used for bacteria mixtures identification and showed high sensitivity (OD600?=?1.0?×?10?6) for V. parahaemolyticus detection. Finally, the sensor array was successfully utilized in the identification of bacteria in pure and mineral bottled water. The?method is low-cost, simple, sensitive, visual, and has potential application in point-of-care testing of bacteria.