Trace detection of S. aureus cells in food samples via RCA-assisted SERS signal amplification with core-shell nanoprobe

Afang Zhu; Waqas Ahmad; Yi Xu; Wenya Wei; Tianhui Jiao; Qin Ouyang; Quansheng Chen

doi:10.1016/j.talanta.2024.127458

Trace detection of S. aureus cells in food samples via RCA-assisted SERS signal amplification with core-shell nanoprobe

Talanta. 2024 Dec 26:286:127458. doi: 10.1016/j.talanta.2024.127458. Online ahead of print.

Authors

Afang Zhu¹, Waqas Ahmad², Yi Xu², Wenya Wei¹, Tianhui Jiao², Qin Ouyang³, Quansheng Chen⁴

Affiliations

¹ School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
² College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, PR China.
³ School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: oyqyf@ujs.edu.cn.
⁴ School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China; College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, PR China. Electronic address: q.s.chen@hotmail.com.

PMID: 39755075
DOI: 10.1016/j.talanta.2024.127458

Abstract

Staphylococcus aureus (S. aureus) has been identified as a indicator of food contamination. In this study, a sensitive and accurate biosensor strategy for S. aureus through rolling circle amplification-assisted surface-enhanced Raman scattering (RCA-assisted-SERS), has been established. The work relies on the interaction between the aptamer and its partial complementary DNA strands fabricated on the surface of gold and silver-assisted magnetic microspheres and the subsequent detachment to trigger the activation of the RCA process. In RCA, template DNA, T4 DNA ligase, and Phi29 DNA polymerase were assembled to form long single-stranded DNA containing repetitive sequences. The gold core encapsulated with a layer of 4-nitrothiophenol and further covered with a silica shell was employed as the SERS nanoprobe (Au@NTP@SiO₂). Subsequently, the output and amplification of SERS signal were performed by hybridizing ssDNA functionalized Au@NTP@SiO₂ to realize the quantitative detection of S. aureus. Under the optimal conditions, S. aureus sensing was monitored (36.0-3.6 × 10⁸ cfu/mL) with a limit of detection of 2.0 cfu/mL. This strategy was further validated for S. aureus recognition in spiked real samples with favorable recoveries (94.0-103.4 %) at p > 0.05. The suggested RCA-assisted SERS approach exhibits potential for multiple foodborne pathogens in both food safety and biomedical investigations.

Keywords: Aptamer; Core-shell nanoparticles; Magnetic microspheres; Rolling circle amplification; Staphylococcus aureus; Surface-enhanced Raman scattering.