Enzymeless determination of cholesterol using gold and silver nanoparticles as electrocatalysts

Resumo

We present the results of synthesis and study of the electrocatalytic activity of gold and silver nanoparticles of different composition (individual metals, core–shell particles, nanoalloys, and particles synthesized electrochemically), immobilized on the surface of a glassy carbon electrode, with respect to cholesterol. A surfactant (cetyltrimethylammonium bromide) is selected to create an aqueous–organic emulsion of cholesterol. It is demonstrated that nanoparticles with a gold core and a silver shell with the regression equation of I = 1.4 × 10^–5c_chol + 5.8 × 10^–5 (R² = 0.97) and silver nanoparticles synthesized electrochemically with the regression equation of I = 1.0 × 10^–5c_chol + 3.0 × 10^–4 (R² = 0.95) possess optimal electrocatalytic characteristics.