A microfluidic colorimetric biosensor for in-field detection of Salmonella in fresh-cut vegetables using thiolated polystyrene microspheres, hose-based microvalve and smartphone imaging APP

Yan Man; Meijing Ban; An Li; Xinxin Jin; Yuanfang Du; Ligang Pan

doi:10.1016/j.foodchem.2021.129578

A microfluidic colorimetric biosensor for in-field detection of Salmonella in fresh-cut vegetables using thiolated polystyrene microspheres, hose-based microvalve and smartphone imaging APP

Food Chem. 2021 Aug 30:354:129578. doi: 10.1016/j.foodchem.2021.129578. Epub 2021 Mar 14.

Authors

Yan Man¹, Meijing Ban², An Li³, Xinxin Jin³, Yuanfang Du³, Ligang Pan⁴

Affiliations

¹ Beijing Research Center for Agricultural Standards and Testing, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China; Risk Assessment Lab for Agro-products (Beijing), Ministry of Agriculture. P.R. China, Beijing 100097, China; Beijing Municipal Key Laboratory of Agriculture Environment Monitoring, Beijing 100097, China. Electronic address: manyan3669@163.com.
² School of Food Science and Engineering, Beijing University of Agriculture, Beijing 102206, China.
³ Beijing Research Center for Agricultural Standards and Testing, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China; Risk Assessment Lab for Agro-products (Beijing), Ministry of Agriculture. P.R. China, Beijing 100097, China; Beijing Municipal Key Laboratory of Agriculture Environment Monitoring, Beijing 100097, China.
⁴ Beijing Research Center for Agricultural Standards and Testing, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China; Risk Assessment Lab for Agro-products (Beijing), Ministry of Agriculture. P.R. China, Beijing 100097, China; Beijing Municipal Key Laboratory of Agriculture Environment Monitoring, Beijing 100097, China. Electronic address: panligang2012@126.com.

PMID: 33756331
DOI: 10.1016/j.foodchem.2021.129578

Abstract

A microfluidic colorimetric biosensor was developed using thiolated polystyrene microspheres (SH-PSs) for aggregating of gold nanoparticles (AuNPs), a novel hose-based microvalve for controlling the flow direction, and a smartphone imaging APP for monitoring colorimetric signals. Aptamer-PS-cysteamine conjugates were used as detection probes and reacted with Salmonella in samples. Complementary DNA - magnetic nanoparticle (cDNA - MNP) conjugates were used as capture probes, reacted with the free aptamer-PS-cysteamine conjugates. AuNPs were aggregated on the surface of Salmonella-aptamer-PS-cysteamine conjugates, resulting in a visible color change in the detection chamber, which indicating different concentrations of Salmonella. The limit of detection was low to 6.0 × 10¹ cfu/mL. The microfluidic biosensor exhibited a good specificity. It was evaluated by analyzing salad samples spiked with Salmonella. The recoveries ranged from 91.68% to 113.76%, which indicated its potential application in real samples.

Keywords: Colorimetric; Foodborne pathogen; Fresh-cut vegetable; Microfluidic chip; Microvalve; Polystyrene microsphere; Smartphone.

MeSH terms

Biosensing Techniques / instrumentation*
Colorimetry / instrumentation*
Gold / chemistry
Lab-On-A-Chip Devices*
Limit of Detection
Metal Nanoparticles
Microspheres
Polystyrenes / chemistry*
Salmonella / isolation & purification*
Smartphone*
Vegetables / microbiology*

Substances

Polystyrenes
Gold