A dual-mode colorimetric and surface-enhanced Raman strategy for chloramphenicol detection based on the Au@Pt nanozyme and EXPAR

• Published in: Microchemical journal Vol. 207; p. 111990
• Main Authors: Zhang, Runzi, Xie, Shunbi, Yang, Jia, Zhang, Lian, Xiong, Renbo, Sun, Hansen, Zhang, Hongcheng, Jiang, Minghang, He, Yi
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.12.2024
• Subjects: Bimetallic nanozyme; Chloramphenicol; Dual-mode aptasenser; EXPAR; Y-shape; Chloramphenicol; EXPAR; Y-shape; Bimetallic nanozyme; Dual-mode aptasenser
• ISSN: 0026-265X
• DOI: 10.1016/j.microc.2024.111990

[Display omitted] •The bimetallic nanozyme Au@Pt not only possessed strong catalytic capabilities, catalyzing the conversion of TMB to oxTMB, but also provided numerous “hotspots,” enhancing the Raman signal.•The exponential isothermal amplification strategy (EXPAR) generated a significant number of amplicons in a short period under isothermal conditions, substantially amplifying the SERS signal and enhancing sensitivity.•The multi-“hotspot” magnetic Fe3O4@Au was used as a SERS substrate, rapidly enriching the Raman signal and improving detection efficiency.•The dual-mode detection strategy achieved a SERS detection limit of 4.96 × 10-13 M and a colorimetric detection limit of 9.23 × 10-9 M. The misuse of chloramphenicol (CAP) has resulted in an escalation of antibiotic-resistant bacterial strains, posing a significant threat to human health. Through the fabrication of magnetic multi-“hotspot” nanoflower particles as SERS substrates and combine bimetallic peroxidase Au@Pt, dual-mode detection of CAP was achieved. The preparation of magnetic nanoparticles Fe3O4@Au facilitated rapid aggregation, enriching a SERS signal. Integrated with the exponential amplification reaction (EXPAR) strategy, under isothermal conditions, a highly rate increase of amplicon production was achieved, thereby binding more nanozyme Au@Pt. In the presence of the target CAP, due to specific binding with the aptamer, the EXPAR was activated, generating a substantial amount of amplicons that formed a stable “Y-shaped” structure with magnetic nanoparticle probes and nanozyme probes. With the addition of TMB, the excellent peroxidase-like activity of the nanozyme oxidized it to oxTMB, resulting in changes in both color and Raman signals. This strategy achieved dual-mode ultra-trace detection of CAP. The SERS detection ranged from 1.0 × 10-12 M to 1.0 × 10-6 M, with a detection limit of 4.96 × 10-13 M; the colorimetric method ranged from 2.5 × 10-7 M to 1.0 × 10-8 M, with a detection limit of 9.23 × 10-9 M. This method offers a new approach and insights for the ultra-trace detection of antibiotics.