Xia et al. 2025 — Whole-cell biosensor with biological digestion circuit for Hg detection in food matrices
This paper describes a whole-cell biosensor augmented with a synthetic biological digestion gene circuit designed to overcome matrix interference during mercury (Hg2+) detection in complex food samples. The gene circuit automates the digestion of organic matter within the bacterial host, eliminating the need for manual acid digestion steps and enabling more direct detection of Hg2+ in food matrices including fish, rice, shellfish, and black beans. The study validates sensor performance using spiked samples and reports recovery rates, but does not measure actual Hg concentrations in commercially sourced or environmental food samples.
Key numbers
- LOD: 0.082 µM (detection limit); LOQ: 0.272 µM
- Validated food matrices: fish, rice, shellfish, black beans (all spiked)
- Recovery rates: satisfactory across all four matrices (exact values in paper tables)
- Published in Foods 2025, 14, 3798 (MDPI)
Methods (brief)
Whole-cell biosensor incorporating a mer-operon-based Hg-responsive gene circuit, modified with a biological digestion cassette expressed in E. coli. Fluorescence signal output correlates with Hg2+ concentration. Method compared against ICP-MS for validation on spiked samples. Total mercury only (not speciated).
Implications
Certification: Not applicable — no occurrence data from commercial or environmental food sources. Courses: Useful as an example of synthetic biology applied to food safety rapid testing, particularly for Hg in seafood and grain matrices. App: No contamination profile data extractable. Microbiome: Not applicable.