Biopolymers and cell. 2008; 24 (2): 135 - 141

Formaldehyde conductometric biosensor based on the recombinant formaldehyde dehydrogenase from Hansenula polymorpha yeast

O. F. Sosovskaya, G. N. Pavlishko, S. Ya. Paryzhak, M. V. Gonchar, Ya. I. Korpan

Gold interdigitated planar electrodes and NAD+- and glutathione-dependent formaldehyde dehydrogenase, isolated from the recombinant strain Tf 11-6 of the thermotolerant yeast H. polymorpha, were used for development of formaldehyde-sensitive conductometric biosensor. Novel approach to the preparation of sensor bioelement, including immobilisation of low-molecular cofactors (NAD+ and glutathione) in bioselective layer as well as allowing multiple assays without addition of the cofactors to the analyzed sample, was proposed. Dependence of biosensor response on analyte concentration, pH value, and buffer concentration was investigated using model samples. Selectivity, operational and storage stabilities of the developed sensor were studied. A linear detection range for formaldehyde was shown to be 1–100 mM.

Keywords: conductometric biosensor, Hansenula polymorpha, NAD+- and glutathione-dependent formaldehyde dehydrogenase, formaldehyde.