Application of hydrophobic palladium nanoparticles for the development of electrochemical glucose biosensor

An amperometric glucose biosensor based on an n-alkylamine-stabilized palladium nanoparticles (PdNPs)-glucose oxidase (GOx) modified glassy carbon (GC) electrode has been successfully fabricated. PdNPs were initially synthesized by a biphase mixture of water and toluene method using n-alkylamines (dodecylamine, C12-NH2 and octadecylamine, C18-NH2) as stabilizing ligands. The performance of the PdNPs-GOx/GC biosensor was studied by cyclic voltammetry. The optimum working potential for amperometric measurement of glucose in pH 7.0 phosphate buffer solution is −0.02 V (vs. Ag/AgCl). The analytical performance of the biosensor prepared from C18-PdNPs-GOx is better than that of C12-PdNPs-GOx. The C18-PdNPs-GOx/GC biosensor exhibits a fast response time of ca. 3 s, a detection limit of 3.0 μM (S/N = 3) and a linear range of 3.0 μM–8.0 mM. The linear dependence of current density with glucose concentration is 70.8 μA cm−2 mM−1. The biosensor shows good stability, repeatability and reproducibility. It has been successfully applied to determine the glucose content in human blood serum samples.