Electrocatalytic-mediated in situ heterojunction formation for amplified electrochemical sensing platform based on Mn-doped Cu(OH)2 hexagonal nanoring

Developing distinct sensing strategies and their rational combination for specific detection has been demonstrated as an efficient approach to boost the analytical performance of electrochemical biosensors. In contrast to existing sensing mechanisms, a novel biocatalytic-mediated method via in-situ combining Mn-doped Cu(OH)2 hexagonal nanoring is designed to form a CuxS-based heterojunction on electrode surface for highly selective hydrogen sulfide (H2S) detection, resulting in an obviously electro-current signal change due to the fast electron transfer rate. Meanwhile, the combination of heterojunction strategy and electrochemical detection can address sulfur poisoning-caused electrode passivation. Atomically dispersed nanocomposites active sites on the sensing interface enhance H2S electrocatalytic activity at a low potential to stimulate electrochemical signals on. This H2S-responsive electrochemical sensing platform exhibits excellent sensitivity, selectivity, and stability. Under optimal experimental parameters, the constructed sensing platform shows a wide linear range for H2S in the range of 0.1-260 mu M, which will promote us better understand the H2S mechanism in complex living systems.