Single Probe-Based Chemical-Tongue Sensor Array for Multiple Bacterial Identification and Photothermal Sterilization in Real Time

Simple and efficient identification of multiple bacteria and sterilization in real time is of considerable significance for clinical diagnostics and quality control in food. Herein, a novel chemical-tongue sensor array with 3,3',5,5'-tetramethylbenzidine (TMB) as a single probe was developed for bacterial identification and photothermal elimination. The synthesized bimetallic palladium/platinum nanoparticles (Pd/Pt_NPs) present excellent catalytic capability that can catalyze TMB into oxidized TMB (oxTMB) with four feature absorption peaks. Bacteria have different ability on inhibiting the reaction between TMB and Pd/Pt_NPs. With the absorbance intensity of oxTMB at the four feature peaks as readout, nine kinds of bacteria including two drug-resistant bacteria can be successfully distinguished via linear discriminant analysis. Remarkably, oxTMB exhibits excellent photothermal properties and can effectively kill bacteria in real time under near-infrared laser irradiation. The strategy of selecting TMB as a single probe simplifies the experimental operation and reduces the time cost. Furthermore, the developed sensing system was used to promote the wound healing process of MRSA-infected mice in vivo. The investigation provides a promising simple and efficient strategy for bacterial identification and sterilization with a universal platform, which has great potential application in clinical diagnosis and therapy.