Pyomelanin-powered whole-cell biosensor for ultrasensitive and selective detection of bioavailable Hg(ii).

ABSTRACT: Rapid, low-cost trace inorganic Hg(ii) detection in environmental waters remains a critical public-health challenge. Here, we engineered Escherichia coli into a naked-eye whole-cell biosensor by coupling a redesigned MerR-Pmer element to the pyomelanin biosynthetic pathway. Three 4-hydroxyphenylpyruvate dioxygenase (HppD) homologs from Aeromonas media WS, Aeromonas hydrophila 4AK4, and Pseudomonas aeruginosa PAO1 were codon-optimized and functionally screened. The sensor strain of TOP10/pHg-PAO1 exhibited the broadest quantitative range (4.9-1250 nM) and the lowest detection limit (1.2 nM), outperforming most fluorescent counterparts. The water-soluble red-brown pyomelanin product was measured directly in the culture supernatants by absorbance at 400 nm,

SUBMITTER: Tang J 

PROVIDER: S-EPMC12379883 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature