This paper reports on a system for sampling atmospheric formaldehyde by dissolution in an aqueous solution followed by the monitoring of the aldehyde using an ion-sensitive field-effect transistor (ISFET) in conjunction wit an enzyme specific for this pollutant. Formaldehyde dehydrogenase from ‘Pseudomonas putida’ was chosen on the basis of its characteristics to be coupled to the ISFET transudcer. This enzyme, using oxidized nicotinamide adenine dinucleoside (NAD) as a cofactor, catalyses the oxidation of a molecule of formaldehyde with the parallel production of two protons, which are sensed by the ISFET. The working conditions were chosen to obtain a linear response of the sensor up to 200 uM formaldehyde. On the basis of the enrichment obtained by the sampling system, the detection limit of 10 uM formaldehyde in aqueous solution, achieved by the ISFET biosensor, corresponds to an atmospheric concentration of the formaldehyde in the ppb range
Potentiometric Detection of Formaldehyde in Air by an Aldehyde Dehydrogenase FET
Lui, Alberto;Margesin, Benno;Zen, Mario;Soncini, Giovanni
1996-01-01
Abstract
This paper reports on a system for sampling atmospheric formaldehyde by dissolution in an aqueous solution followed by the monitoring of the aldehyde using an ion-sensitive field-effect transistor (ISFET) in conjunction wit an enzyme specific for this pollutant. Formaldehyde dehydrogenase from ‘Pseudomonas putida’ was chosen on the basis of its characteristics to be coupled to the ISFET transudcer. This enzyme, using oxidized nicotinamide adenine dinucleoside (NAD) as a cofactor, catalyses the oxidation of a molecule of formaldehyde with the parallel production of two protons, which are sensed by the ISFET. The working conditions were chosen to obtain a linear response of the sensor up to 200 uM formaldehyde. On the basis of the enrichment obtained by the sampling system, the detection limit of 10 uM formaldehyde in aqueous solution, achieved by the ISFET biosensor, corresponds to an atmospheric concentration of the formaldehyde in the ppb rangeI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
