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

Hydrogen sulfide (H2S) 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 H2S based on the chemical reaction between copper oxide (CuO and Cu2O) and hydrogen sulfide (including H2S and HS-) at a neutral solution (pH 7.4). Interestingly, when Na2S exists, copper and its oxide can be converted into Cu2S and CuS, resulting in an increase in the oxidation peak current of Cu2S-CuS with the increase of Na2S concentration, which is a direct evidence confirming the excellent sensor for the H2S detection. More importantly, the linear relationship between the oxidation peak currents of Cu2S-CuS and Na2S concentration is observed from 0.4 mu M to 400 mu M with a low detection limit of 0.2 mu M, and satisfying selectivity. The developed strategy may have a great potential for further understanding the roles that biological H2S plays in biological systems.