An Optical Halitosis (Bad Breath) Sensor with Mao-A

Methyl mercaptan (MM: CH3SH) is known as one of major chemicals of halitosis (bad breath). Monoamine oxidase type-A (MAO-A) has been reported to catalyze the oxidation of methyl mercaptan for a xenobiotic metabolism in human liver. In this research, an oxygen sensitive optical fiber was applied for developing a optical bio-sniffer for methyl mercaptan in halitosis. An optical bio-sniffer was constructed by applying an MAO-A immobilized membrane onto the fiber-tip with a tube-ring. The optical device was possible to detect the oxygen consumption induced by MAO-A enzymatic reaction with methyl mercaptan as an index of halitosis level. As the result of the physiological application, the bio-sniffer could be successfully used the halitosis monitoring.