This paper describes the experimental studies on the performance of a novel amperometric electrochemical sensor that utilizes the unique chemical and electrochemical properties of nonaqueous aprotic solvent mixture based electrolyte solution containing a stable salt used in the electrochemical cell. The nonaqueous electrolyte solution is nontoxic and has very low vapor pressure. It is electrochemically very stable with inert electrodes capable of operating from 0 to -2.5 V and 0 to +2.5 V vs silver quasi reference or platinum pseudo reference electrode. The electrolyte solution has an order of magnitude high solubility for gases and organic vapors. The sensor with this electrolyte and a three electrode structure cell can be used for the detection and monitoring of gases and organic vapors with high selectivity and sensitivity. Two or more gases and/or vapors of chemical species can be determined almost simultaneously with the sensor using the technique of scanning voltammetry. Experimental results obtained on the detection of various gases and organic vapors will be presented along with possible reaction mechanisms for sensing.