NIR-driven multifunctional PEC biosensor based on aptamer-modified PDA/MnO < sub > 2 < /sub > photoelectrode for bacterial detection and inactivation

Biosens Bioelectron. 2024 Apr 20;257:116320. doi: 10.1016/j.bios.2024.116320. Online ahead of print.ABSTRACTSensitive detection and effective inactivation of bacteria are essential in preventing foodborne bacterial infection that poses a significant threat to human health. Herein, a near-infrared (NIR)-driven multifunctional photoelectrochemical (PEC) biosensor was constructed for detection and inactivation of S. aureus. Based on the covalent bonding between amine and carboxyl groups, carboxyl-functionalized SA31 aptamer was immobilized on the PDA/MnO2 photoelectrode. In the presence of S. aureus, SA31 aptamer can specifically capture S. aureus, causing the decrease of photocurrent signal owing to steric hindrance effect. Leveraging photocurrent-off signal, there existed a satisfied linear relationship between the photocurrent variation and the logarithm of S. aureus concentration, achieving a wide linear range from 10 to 107 CFU/mL with a low detection limit of 2.0 CFU/mL. Notably, PDA/MnO2 with peroxidase-like activity facilitated the catalytic oxidation of S. aureus with assistance of hydrogen peroxide (H2O2) to cause the inactivation of S. aureus. Desorption of inactivated S. aureus from the photoelectrode led to a recovery of photocurrent signal, enabling a "signal on" switch. Simultaneously, the excellent photothermal performance of the PDA/MnO2 converted light energy into heat energy under the irradiation of NIR light (808 nm, 1.5 W/cm2), triggering the synergistic ant...

Source: Biosensors and Bioelectronics - April 25, 2024 Category: Biotechnology Authors: Anni Cui Lihua Dong Yiting Hou Xin Mu Yu Sun Huan Wang Xiahua Zhong Guiye Shan Source Type: research