Nanochemistry and biotechnology

Development of a highly sensitive arginine biosensor based on ammonium-selective sublayer within the sensor recognition element

Saiapina O.Y.1, Dzyadevych S.V.1,2, Jaffrezic-Renault N.3

1 Laboratory of Biomolecular Electronics, Institute of Molecular Biology and Genetics of the NAS of Ukraine. 150, Zabolotnogo Str., Kyiv-03680, Ukraine.
E-mail: oysaiapina@gmail.com
2 Institute of High Technologies, Taras Shevchenko National University of Kyiv. 4H, Hlushkova Ave., Kyiv-03022, Ukraine.
3Laboratory of Analytical Sciences, University Claude Bernard Lyon 1, 43 Boulevard du 11 Novembre 1918, Villeurbanne Cedex, 69622, France

Accurate, affordable and easy-to-perform methods for selective determination of individual components in the foods and food supplements is essential for the development of efficient methods of their quality control. The foods enriched with L-arginine (Arg) and arginine-based food supplements have found widespread application over the last 10-15 years due to the multiple reports on positive effect of increased doses of Arg in treating a number of health conditions and disorders in the human body. 
This work aimed at developing a novel highly sensitive and selective conductometric sensor for Arg determination using arginase coupled with urease and deposited over the clinoptilolite (CLT). Natural zeolite clinoptilolite, known for its pronounced selectivity towards  species, was employed by us targeting the main goal of ammonium mediated signal enhancement. The arginine biosensor was designed based on the enzymatic conversion of arginine by arginase (EC 3.5.3.1) and urease (EC 3.5.1.5) followed by the  capture by zeolite.
The limit of detection, the linear and dynamic ranges of the developed biosensor were studied and compared to the corresponding analytical characteristics of the arginine biosensor which was not modified with CLT. It was shown that the enzyme immobilization on the CLT sublayer allowed sensing Arg with higher sensitivity and within the wider concentration ranges in comparison with the control biosensor. The arginine biosensor based on the enzyme/CLT membrane had limit of detection of 3×10-7 M arginine, dynamic range of 0-65 mM arginine and linear range of 0-3 mM arginine. The obtained results can be used as a background for viewing the CLT-based modification as a powerful approach for the enhancement of the -mediated signals in conductometric sensors.