PdCu alloy nanosheets-constructed 3D flowers: New highly sensitive materials for H2S detection

Hydrogen sulfide (H 2 S) could be directly produced in mammals and recognized as a third gasotransmitter, which are closely associated with physiological and pathological processes. However, the detailed mechanism remains unclear, mainly due to a lack of robust sensors to accurately and quantitatively detect its concentrations in biological samples. Herein, for the first time, we develop a new electrochemical sensor for the detection of H 2 S based on the chemical reaction between copper oxide (CuO and Cu 2 O) and hydrogen sulfide (including H 2 S and HS − ) at a neutral solution (pH 7.4). Interestingly, when Na 2 S exists, copper and its oxide can be converted into Cu 2 S and CuS, resulting in an increase in the oxidation peak current of Cu 2 S-CuS with the increase of Na 2 S concentration, which is a direct evidence confirming the excellent sensor for the H 2 S detection. More importantly, the linear relationship between the oxidation peak currents of Cu 2 S-CuS and Na 2 S concentration is observed from 0.4 μM to 400 μM with a low detection limit of 0.2 μM, and satisfying selectivity. The developed strategy may have a great potential for further understanding the roles that biological H 2 S plays in biological systems.