Capacitive carbon dot electronic nose for bacterial detection

A capacitive carbon dots (C-dots)-based electronic nose (e-nose) has been developed. The sensing scheme relies on the adsorption of bacterially secreted volatile molecules onto electrodes, each coated with C-dots exhibiting different polarities. The varying affinities of volatile molecules having different polarities to the electrode-deposited C-dots gave rise to distinct capacitance changes. Capacitance transformations recorded from three C-dot-coated electrodes gave rise to “capacitive fingerprints” for different bacteria, providing the means for distinguishing among microbial species. The capacitive C-dot e-nose was constructed from inexpensive and environmentally benign building blocks, is recyclable and easy to use, and constitutes a powerful platform for gas sensing in general, and bacterial detection in particular.