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Updated: May 13, 2025

Fabricating a UV-Vis and Raman Spectroscopy Immunoassay Platform
Published on: November 10, 2016
A colorimetric and surface-enhanced Raman scattering dual-mode "sandwich" immunosensor for ultrasensitive detection
Sijia Hu1, Tao Huang2, Fulai Li3
1College of Food Science and Engineering, Ningbo University, Ningbo, Zhejiang Province, 315211, China.
Abstract:
Herein, a dual-mode approach combining colorimetry and surface-enhanced Raman scattering (SERS) were developed for Salmonella detection. Immunomagnetic beads were used to separate and concentrate the Salmonella. And the GOx@ZIF-90@PDA@pAbs were used as signal probe to catalyze glucose to form H2O2. In the presence of H2O2, tyramine (TYR) aggregation was brought on by HRP-catalyzed phenol polymerization, which led to the aggregation of AuNPs through the strong electrostatic interactions between TYR and AuNPs. Based on the enzymatic cascade catalyzed signal amplification induced AuNPs aggregation, the dual-mode method exhibited wide linear range (101-105 CFU/mL) and high sensitivity. The limit of detection (LOD) of colorimetric mode was 34 CFU/mL, while the LOD was 5 CFU/mL in SERS mode, which was 6.8-fold lower than that of colorimetric mode. Furthermore, the two modes demonstrated high specificity and applicability, which might be a promising method for rapid and sensitive detection of Salmonella to ensure food safety.

