Target Recognition-Triggered Interfacial Electron Transfer Model: Toward Signal-On Photoelectrochemical Aptasensing for Efficient Detection of Staphylococcus aureus Using Ti3C2Tx-Au NBPs/ZnO NR Composites

Ao Huang; Xiuxiu Dong; Guanghui Shen; Lilong He; Chaoyang Cai; Qian Liu; Qijian Niu; Chunxiang Xu

doi:10.1021/acs.langmuir.4c02104

Target Recognition-Triggered Interfacial Electron Transfer Model: Toward Signal-On Photoelectrochemical Aptasensing for Efficient Detection of Staphylococcus aureus Using Ti₃C₂T_x-Au NBPs/ZnO NR Composites

Langmuir. 2024 Sep 20. doi: 10.1021/acs.langmuir.4c02104. Online ahead of print.

Authors

Ao Huang¹, Xiuxiu Dong¹, Guanghui Shen², Lilong He¹, Chaoyang Cai¹, Qian Liu¹, Qijian Niu¹, Chunxiang Xu³

Affiliations

¹ Key Laboratory of Modern Agricultural Equipment and Technology (Jiangsu University), Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China.
² Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology/Key Laboratory for Agro-product Safety Risk Evaluation (Nanjing), Ministry of Agriculture and Rural Affairs/Collaborative Innovation Center for Modern Grain Circulation and Safety/Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, Jiangsu 210014, China.
³ School of Electronic Science & Engineering, Southeast University, Nanjing, Jiangsu 210096, China.

PMID: 39302020
DOI: 10.1021/acs.langmuir.4c02104

Abstract

Staphylococcus aureus (S. aureus) is one of the most common foodborne pathogens worldwide, which poses a great threat to public health. It is of utmost importance to develop rapid, simple, and sensitive methods for the determination of S. aureus. A signal-on photoelectrochemical (PEC) aptasensor is constructed herein based on titanium carbide (Ti₃C₂T_x)-Au nanobipyramids (NBPs)/ZnO nanoarrays (NRs). The reliability and capability of the PEC aptasensor make it suitable for the sensitive and selective determination of S. aureus. First, the electrostatically self-assembled Ti₃C₂T_x-Au NBP nanomaterial was coated on the ZnO NR surface by a spin-coating method. On the one hand, Ti₃C₂T_x-Au NBPs can broaden the spectral absorption of ZnO NRs, resulting in Ti₃C₂T_x-Au NBPs/ZnO NR composites that exhibit a wide range of absorption from the ultraviolet to the infrared region. On the other hand, Ti₃C₂T_x can reduce the agglomeration of nanoparticles, while Au NBPs can effectively fix the aptamer through the Au-S bond. Specifically, the experimental results show that when S. aureus is present, the Au NBPs-aptamer-S. aureus complex is shed from the electrode surface, altering the interfacial electron transfer model and reducing the steric hindrance. Consequently, an amplified photocurrent signal for the quantitative determination of S. aureus is obtained. Under optimal experimental conditions, a linear correlation is observed between the current response of the aptasensor and the logarithm of the S. aureus concentration (ranging from 1.0 to 1.0 × 10⁶ CFU/mL), with an impressive detection limit as low as 0.5 CFU/mL. Furthermore, the aptasensor has been successfully employed for the detection of S. aureus in milk, with the recovery of 93.0%-99.0%. Hence, this research offers a novel approach for the detection of foodborne pathogens and other noxious substances.