Effect of different modifications of BEA-zeolites on operational characteristics of conductometric biosensor

Effect of different modifications of zeolite Na+-BEA on working characteristics of urease-based conductometric biosensor was studied. As the biosensor sensitive elements were used bioselective membranes based on urease and various zeolites immobilised with bovine serum albumin on the surface of conductometric transducers. Influence of zeolites on sensitivity of urea biosensor was investigated as well as reproducibility of biosensor signal and reproducibility of activity of the bioselective element after different variants of urease immobilisation on the surface of conductometric transducer. The biosensors based on zeolites (NH4+-BEA 30 and H+-BEA 30) were shown to be the most sensitive. Concentration of these zeolites in the bioselective membrane was optimized. Use of zeolites modified with methyl viologen and silver was ascertained to be of no prospect for urea conductometric biosensors. It was demonstrated that characteristics of urea biosensors can be regulated, varying zeolites modifications and their concentrations in bioselective membranes.

► We used BEA-zeolites to improve characteristics of the biosensor.
► Usage of several zeolites results in increasing biosensor response.
► Inter-assay is improved when NH4+-BEA 30 is added to the bioselective membrane.
► Properties of the biosensor can be regulated by varying zeolite modifications.