Sensitive biosensors based on (dendrimer encapsulated Pt nanoparticles)/enzyme multilayers

A sensitive enzymed-based biosensor for glucose has been obtained by introducing dendrimer encapsulated Pt nanoparticles via a layer-by-layer assembling method. The free amine groups located on each poly(amidoamine) dendrimer molecule were exploited to covalently attach enzyme to the dendrimer chains using carbodiimide coupling. The resultant enzyme electrodes are shown to have excellent sensitivity (as high as 30.33 mu A mM(-1) cm(-2)) and a limit of detection (about 0.1. mu mol L-1), depending on metal nanoparticles within dendrimers and the biocompatibility of dendrimers, the linear response range to glucose (from 5 mu M to 1.0 mM), a fast response time (within 5 s), and good reproducibility (< 8% relative standard deviation between electrodes at low substrate concentration). ne sensitivities, and stabilities determined experimentally have demonstrated the potential of dendrimer encapsulated Pt nanoparticles as a novel candidate for enzymatic glucose biosensors.