Carbon-dot–hydrogel for enzyme-mediated bacterial detection

A hybrid carbon-dot (C-dot)–hydrogel matrix was constructed and employed for detection of bacteria. The transduction mechanism is novel, based upon cleavage of ester bonds within the hydrogel scaffold by bacterially-secreted esterases; the ensuing fluidization of the hydrogel resulted in aggregation of the embedded C-dots and consequent quenching of their fluorescence. We show that the C-dot–hydrogel exhibits high sensitivity and can distinguish among bacterial species through modulation of the emitted fluorescence, depending upon their esterase secretions.