Active Pt Nanoparticles Stabilized with Glucose Oxidase

We report the growth of Pt nanoparticles (NP) coupled and stabilized in situ with glucose oxidase (GOx). The enzyme-capped-Pt nanoparticles were formed from K 2 PtCl 6 (aq) reduced with H 2 (g) in the presence of GOx at a molar ratio of 889/1 Pt(IV)/GOx, creating a direct-linkage between NP and protein during particle growth. Transmission electron microscopy imaging revealed the formation of fcc Pt nanocrystals in the presence of the enzyme with an average dimension < d > = 4.05 ± 0.62 nm, whereas in its absence Pt black precipitated from solution. This is evidence that the glycoprotein terminated propagation of Pt growth and stabilized the NP surface. Transfer of Pt NP−GOx to an electrode by assembly on poly(diallyldimethylammonium chloride) allowed amperometric glucose determination with a low limit of detection of ca. 30 μM.