The proposed research offers an innovative approach to the commercial development of in vivo and in vitro S-nitrosothiols (RSNO) sensors. The design of selective and sensitive RSNO sensors and related instrumentation will be undertaken for a wide range of biological applications. The use of sensitive nitric oxide electrochemical sensors coupled with a Cu(I) ion generator and delivery system, demonstrates detection of RSNOs in the nanomolar range. The RSNO sensors would offer preferential detection of both low and high molecular weight (protein) RSNOs. The following aims will be pursued in this proposal (1) the RSNO sensor, further combines with HPLC system to separate and detect different RSNOs on line 2) development and commercialization of an electronic controller instrument for use with RSNO sensors, (3) development of new RSNO sensors suitable for biological sampling (4) biological field testing of the RSNO detector and instrumentation. These goals will be reached with significant electroanalytical, bioanalytical development and detailed biological studies. The proposed research will capitalize upon the group's recent advances in NO nanosensors, microchip sensors, and a novel micromixer and Cu(I) generator. The long term goal of the proposed project is to create commercially viable and robust instrumentation with which to measure the concentration of S-nitrosothiols rapidly, selectively and with sensitivity capable of detecting these species in the biologically relevant concentration range. [unreadable] [unreadable]