Nitric oxide sensor

摘要

An electrode sensor which may be used to specifically and quantitatively measure nitric oxide is provided, as well as a method of preparing and using such an electrode sensor to measure nitric oxide concentration in solution. A nitric oxide (NO) microsensor based on catalytic oxidation of NO comprises a thermally-sharpened carbon fiber with a tip diameter of about 0.5-0.7 mu m coated with several layers of p-type semiconducting polymeric porphyrin and cationic exchanger deposited thereon. The microsensor, which can be operated in either the amperometric, voltammetric or coulometric mode utilizing a two or three electrode system, is characterized by a linear response up to about 300 mu M, a response time better than 10 msec and a detection limit of about 10 nM. The sensor of the present invention also discriminates against nitrite, the most problematic interferant in NO measurements. The amount of NO released from a single cell can thus be selectively measured in situ by a porphyrinic microsensor of the invention. A larger scale sensor utilizing porphyrin and cationic exchanger deposited on larger fibers or wires, platinum mesh or tin indium oxide layered on glass, can also be employed when measurement of NO concentration in chemical media, tissue or cell culture is desired.