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A Paper-Chip-Based Phage Biosensor Combined with a Smartphone Platform for the Quick and On-Site Analysis of E. coli O157:H7 in Foods

Authors :
Chaiyong Wu
Dengfeng Li
Qianli Jiang
Ning Gan
Source :
Chemosensors, Vol 11, Iss 2, p 151 (2023)
Publication Year :
2023
Publisher :
MDPI AG, 2023.

Abstract

The rapid and specific point-of-care (POC) analysis of virulent pathogenic strains plays a key role in ensuring food quality and safety. In this work, a paper-based fluorescent phage biosensor was developed for the detection of the virulent E. coli O157:H7 strain (as the mode of virulent pathogens) in food samples. Firstly, phages that can specifically combine with E. coli O157:H7 (E. coli) were stained with SYTO-13 dye to prepare a novel fluorescent probe (phage@SYTO). Simultaneously, a micro-porous membrane filter with a pore size of 0.45 μm was employed as a paper chip so as to retain the E. coli-phage@SYTO complex (>1.2 μm) on its surface. The phage@SYTO (200 nm in size) was able to pass through the pores of the chip, and the complex could be retained on the paper chip using the free phage@SYTO probes. The E. coli-phage@SYTO could emit a visual fluorescent signal (excited at 365 nm; emitted at 520 nm) onto the chip, which could be detected by a smartphone to reflect the concentration of E. coli. Under optimized conditions, the detection limit was as low as 50 CFU/mL (S/N = 3) and exhibited a wide linear range from 102 to 106 CFU/mL. The sensor has potential application value for the quick and specific POCT detection of virulent E. coli in foods.

Details

Language :
English
ISSN :
22279040
Volume :
11
Issue :
2
Database :
Directory of Open Access Journals
Journal :
Chemosensors
Publication Type :
Academic Journal
Accession number :
edsdoj.134f03b0235d490a89151c13dc526109
Document Type :
article
Full Text :
https://doi.org/10.3390/chemosensors11020151