Rational Design of Specific Recognition Molecules for Simultaneously Monitoring of Endogenous Polysulfide and Hydrogen Sulfide in the Mouse Brain

A biosensor was created for the simultaneous monitoring of endogenous H₂S_n and H₂S in mouse brains and exploring their roles in activation of the TRPA1 channel under two types of brain disease models: ischemia and Alzheimer's disease (AD). Based on DFT calculations and electrochemical measurements, two probes, 3,4-bis((2-fluoro-5-nitrobenzoyl)oxy)-benzoic acid (M_PS-1) and N-(4-(2,5-dinitrophenoxy) phenyl)-5-(1, 2-dithiolan-3-yl)pentanamide (M_HS-1), were synthesized for specific recognition of H₂S_n and H₂S. Through co-assembly of the two probes at the mesoporous gold film with good anti-biofouling ability and electrocatalytic activity, this microsensor showed high selectivity for H₂S_n and H₂S against potential biological interferences. The biosensor can simultaneously determine the concentration of H₂S_n from 0.2 to 50 μm, as well as that of H₂S from 0.2 to 40 μm. The expression of TRPA1 protein positively correlated with levels of H₂S_n under both ischemia and AD.