Electrogenerated chemiluminescence sensor for glutathione with $$ Ru\left( {bpy} \right)_3^{2+ } $$ -doped silica nanoparticles

Abstract

An electrogenerated chemiluminescence (ECL) sensor for reduced glutathione was developed based on $$ \mathrm{Ru}\left( {\mathrm{bpy}} \right)_3^{2+ } $$ -doped silica nanoparticles-modified gold electrode (Ru-DSNPs/Au). These uniform Ru-DSNPs (about 58 + 4 nm) were prepared by a water-in-oil microemulsion method and characterized by transmission electron microscope and scanning electron microscope. With such a unique immobilization method, a considerable $$ \mathrm{Ru}\left( {\mathrm{bpy}} \right)_3^{2+ } $$ was immobilized three dimensionally on the electrode, which could greatly enhance the ECL response and thus result in an increased sensitivity. The ECL analytical performances of this sensor for reduced glutathione based on the quenched ECL emission of $$ \mathrm{Ru}\left( {\mathrm{bpy}} \right)_3^{2+ } $$ have been investigated in detail. Under the optimum condition, the ECL intensity was linear with the reduced glutathione concentration in the range of 1.0 × 10−9 to 1.0 × 10−4 mol L−1 (R = 0.9971). This method has been successfully applied for the determination of reduced glutathione in serum samples with satisfactory results. The as-prepared ECL sensor for the determination of reduced glutathione displayed good sensitivity and stability.