Work

A Microfluidic Biosensor for Quantitative Detection of Salmonella in Traditional Chinese Medicine

Year: 2024

Type: article

Abstract: Microbial contamination is an important factor threatening the safety of Chinese medicine preparations, microfluidic detection methods have demonstrated excellent advantages in the application of rapid bacterial detection. In our study, a novel optical biosensor was developed for the rapid and sensitive detection of Salmonella in traditional Chinese medicine on a microfluidic chip. Immune gold@platinum nanocatalysts (Au@PtNCs) were utilized for specific bacterial labeling, while magnetic nano-beads (MNBs) with an additional magnetic field were employed for the specific capture of bacteria. The immune MNBs, immune Au@PtNCs, and bacterial samples were introduced into the micro-mixing zone for thorough mixing, resulting in the formation of a double-antibody sandwich structure due to antigen–antibody immune reactions. Subsequently, the mixture flowed into the reaction cell, where the MNBs-Salmonella-Au@PtNCs complex was captured by the magnetic field. After washing, hydrogen peroxide-tetramethylbenzidine substrate (H2O2-TMB) was added, reacting with the Au@PtNCs peroxidase to produce a blue reaction product. This entire process was automated using a portable device, and Salmonella concentration was analysed via a phone application. This simple biosensor enabled Salmonella detection at concentrations as low as 90 CFU/mL within 74 min.

Source: Biosensors

DOI: 10.3390/bios15010010