Hydrogen Sulfide Electrochemical Sensor This new hydrogen sulfide sensor offer a simple, direct method for its in situ measurements. The optimizations of the sensors’ material, applied potential and choosing the proper coating can provide a very good selectivity against biologically relevant species such as nitric oxide, oxygen, hydrogen peroxide, carbon monoxide, ascorbic acid, nitrite, and nitrate. Since there is no hydrogen sulfide-selective membrane, so far, absolute selectivity is not achieved, yet. Sensors based on electrochemical mediators can suffer from interferences, since many oxidizing-reducing species can pass through the gas membrane and chemically reduce/oxidize the mediator such as hydrogen peroxide. Major Features   Small tip diameter, 250 micron or as requested. 4 mm tip length, can be changed upon request. Fast response time. No electrolyte to fill or change. Solid state structure. Very good selectivity against biologically relevant materials at the physiological level. Very wide linear range, from low nanomolar to hundreds of micromolar. Detection limit approaching 10 nM. Additions of 50, 100, 200 and 400 nanomolar H2S to a stirred solution. The sensor has a tip diameter of 250 micron. Applied voltage of 0.35 V. The results were recroded using inNO-T meter/data acquisition system