Progress in Fluorescence Biosensing and Food Safety towards Point-of-Detection (PoD) System

Abstract

The detection of pathogens in food substances is of crucial concern for public health and for the safety of the natural environment. Nanomaterials, with their high sensitivity and selectivity have an edge over conventional organic dyes in fluorescent-based detection methods. Advances in microfluidic technology in biosensors have taken place to meet the user criteria of sensitive, inexpensive, user-friendly, and quick detection. In this review, we have summarized the use of fluorescence-based nanomaterials and the latest research approaches towards integrated biosensors, including microsystems containing fluorescence-based detection, various model systems with nano materials, DNA probes, and antibodies. Paper-based lateral-flow test strips and microchips as well as the most-used trapping components are also reviewed, and the possibility of their performance in portable devices evaluated. We also present a current market-available portable system which was developed for food screening and highlight the future direction for the development of fluorescence-based systems for on-site detection and stratification of common foodborne pathogens.

Keywords: PoC device; biosensing; fluorescence microscopy; food pathogen; microfluidic.

Figure 1

The schematic diagram presents the fundamental components for designing a fluorescence biosensing platform for food sensing. The food analytes (microbes, pesticides, adulterants, pollutants) are detected by using the specific bioreceptors (proteins, enzymes, cells, DNA) generated against various toxins/pesticides/adulterants, etc. These bioreceptors are coupled with bioprobes (nanoparticles, CNT, graphenes, quantum dots, etc.) that are fluorescently active to generate a fluorescent signal (MEF, FERT) response.

Figure 2

Variety of nanomaterials and their surface modifications used in biosensing of food toxins/pathogens like metallic nanoparticles such as AgNPs (Silver nanoparticles), AuNPs (Gold nanoparticles), carbon nanomaterials viz. QDs (Quantum Dots), GO/rGO (Graphene oxide), carbon nanotubes and other MoFs (Metal organic frameworks), Silica nanoparticles, Microspheres, Phosphors, etc. materials.

Figure 3

(A) PDMS microfluidic-platform-based study reports QD fluorescent-probe-based detection of Salmonella typhimurium. (i) Schematic presentation of microfluidic channel with inlet and outlet and presentation of the experimental process and (ii) the bacterial load was determined with LoD of 43 CFU/mL in food samples using the laser b. Copyright (2020), with permission from MDPI [94]. (B) Immunomagnetic separation with fluorescent-labeled sample and (i) video-processed using smartphone for detection of Salmonella with an LoD of 58 CFU/mL and (ii,iii) the efficiency of salmonella detection compared to other bacteria and bacterial-capturing mechanism with nanoparticle, respectively. Copyright (2019), with permission from Elsevier [95]. (C) Shin et al. presented a (i) CD-disk-type microfluidic system for lateral-flow assay, (ii) the assembly of lateral-flow assay, and (iii) multiplexed detection of E. coli, Salmonella Typhimurium, Staphylococcus aureus, and Bacillus cereus in contaminated lettuce samples. Copyright (2018), with permission from the American Chemical Society [96].

Figure 4

(A) Paper-based microfluidics assembly for multiplexed assay. (B) Nanoparticle surface modification and building with ssDNA and blocking BSA protein for detection of E. coli O157:H7 and S. typhimurium. (C) Sensor detecting whole-cell food pathogen with an LoD of 10³ and 10⁴ CFU/mL, respectively. Copyright (2022), with permission from Elsevier [101].