S-nitrosothiol detection via amperometric nitric oxide sensor with surface modified hydrogel layer containing...

A novel electrochemical device for the direct detection of S-nitrosothiol species (RSNO) is proposed by modifying an amperometric nitric oxide (NO) gas sensor with thin hydrogel layer containing an immobilized organoselenium catalyst. The diselenide, 3,3'-dipropionicdiselenide, is covalently coupled to primary amine groups in polyethylenimine (PEI), which is further cross-linked to form a hydrogel layer on a dialysis membrane support. Such a polymer film containing the organoselenium moiety is capable of decomposing S-nitrosothiols to generate NO(g) at the distal tip of the NO sensor. Under optimized conditions, various RSNOs (e.g., nitrosocysteine (CysNO), nitrosoglutathione (GSNO), etc.) are reversibly detected at