A reusable QCM biosensor with stable antifouling nano-coating for on-site reagent-free rapid detection of E. coli O157:H7 in food products
| Authors | |
|---|---|
| Year of publication | 2024 |
| Type | Article in Periodical |
| Magazine / Source | Food Control |
| MU Faculty or unit | |
| Citation | |
| Web | https://www.sciencedirect.com/science/article/pii/S0956713524004122 |
| Doi | http://dx.doi.org/10.1016/j.foodcont.2024.110695 |
| Keywords | Antifouling coating; E. coli O157:H7 detection; QCM biosensor; On-site analysis; Reusability |
| Attached files | |
| Description | Numerous biosensors have shown exceptional analytical performance under laboratory conditions, yet only a few are capable of on-site use with complex, non-model samples while exhibiting reliable analytical performance. Here, we present a new portable biosensor for the rapid (30 min) and accurate detection of bacterial agents in “real-world” food samples, which are originally in either solid or liquid form. The biosensor combines well-established quartz crystal microbalance (QCM) technology, with innovative terpolymer brush nano-coatings on the sensing surface to efficiently reduce non-specific fouling from food samples. Following reagent-free sample preparation, where solid food samples are homogenized, we validated the sensor's detection capabilities on native pathogenic Escherichia coli O157:H7 (E. coli O157:H7) in hamburgers, Czech dumplings, and milk. We achieved limits of detection (LOD), as low as 7.5 × 10^2 CFU/mL in milk, a value approaching fundamental QCM limits, using a simple direct detection assay format. The biosensor's exceptional reusability was demonstrated through 60 sequential hamburger sample injections, resulting in only a minor LOD shift toward the end of series. A 10-min sonication treatment during sample preparation significantly enhanced sensitivity for E. coli O157:H7 in hamburgers and dumplings, yielding LODs as low as 3.1 × 10^3 CFU/mL and 2.6 × 10^4 CFU/mL, respectively. For on-site analysis, we integrated the nano-coated sensing chip into a custom-built four-channel portable QCM biosensor with an optimized microfluidic system, which can be produced on a scale suitable for practical deployment. |
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