УДК 577.151.4+543.555
I.S. KUCHERENKO1,2, О.О. SOLDATKIN1, SE?KIN ?ZT?RK3, BURCU AKATA3, A.P. SOLDATKIN1,2, S.V. DZYADEVYCH1,2
Silicalite as a promising carrier for urease immobilization by adsorption
1Institute of Molecular Biology and Genetics, Kyiv;
2 Taras Shevchenko National University of Kyiv, Kyiv
3Middle East Technical University, Ankara
Introduction. Standardization of the method of immobilization of biomaterial onto transducer surface is a key stage in biosensor commercialization. Despite intensive investigations aimed at stabilization of methods of enzyme immobilization, there is still no sufficient achievement in the subject. Thus, improvement of the methods of biomaterial immobilization remains an actual challenge in biosensorics. The standard adsorption procedure is the simplest method of enzyme immobilization, however this approach is far from optimal because of requirement of large amount of enzymes and their gradual wash-out.
New possibilities in optimization of adsorption are associated with the advancement in nanotechnology, which means improvement of the methods of synthesis of nanoparticles with given properties, in particular, of silicalite used in our work.
Aim. To study a possibility of efficient urease adsorption on silicalite and to compare this approach with other methods of immobilisation.
Methods. Conductometric method of measurement was used. This method is based on measuring conductivity of solution between two pairs of electrodes. Urease-based bioselective membranes were deposited on the first pair, and referent membranes with bovine serum albumin – on the second.
Results. The conventional in biosensorics methods of urease immobilization are compared with the developed by us method of the enzyme adsorption on silicalite. The duration of urease adsorption on silicalite is optimized. The dependences of biosensor response on pH and ionic strength of the working solution are plotted. Intra-reproducibility of the biosensors developed, their operational and storage stability are investigated.
Conclusion. In the work a possibility of urease adsorption on silicalite was shown; the efficiency of this process was demonstrated to be not less than that of other methods of immobilization. Moreover, adsorption on silicalite is notable by some advantages – simple and fast performance, non-use of toxic compounds, high intra-reproducibility. These characteristics are especially important from the viewpoint of commercialization and industrial manufacture of biosensors.