Elaboration of Urease Adsorption on Silicalite for Biosensor Creation

A possibility of efficient urease adsorption on silicalite for the purpose of biosensor creation was investigated. The procedure of urease adsorption on silicalite is notable for such advantages as simple and fast performance and non-use of toxic or auxiliary compounds. Optimal conditions for modifying transducer surfaces with silicalite and subsequent urease adsorption on these surfaces were selected. The working parameters of the created biosensor were optimized. The developed biosensor with adsorbed urease was characterized by good intra-reproducibility (RSD 4.5?%), improved inter-reproducibility (RSD of urea determination is 9?%) and operational stability (less than 10?% loss of activity after 10 days). Besides, the developed method for enzyme adsorption on silicalite was compared with the traditional methods of urease immobilization in biosensorics. Working conditions of the produced biosensor (pH and ionic strength) were shown to be close to those of the biosensor based on urease immobilized in GA vapor. For these reasons, it was concluded that the method of enzyme adsorption on silicalite is well-suited for biosensor standardization aimed at its further manufacture.