Nanostructured platinum-lipid bilayer composite as biosensor

The present work describes the preparation of supported bilayer lipid membrane (s-BLM) doped with metal nanoparticles for the design of biosensors. Platinum (Pt) nanoparticles were deposited through s-BLM to build a hybrid device of nanoscale electrode array by potential cycling in 1 mM K2PtCl6 solution containing 0.1 M KCl. The properties of Pt nanoparticle-doped s-BLM composite were then characterized by cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM). Our results showed that Pt nanoparticles grew in voids of the s-BLMs, through which the underlying glassy carbon (GC) electrode was connected, with maximum length extended out of the lipid membrane around 40 nm. Doping of Pt nanoparticles through s-BLM increased the membrane capacitance and decreased the membrane resistance of s-BLM. Pt nanoparticles array in s-BLM electrocatalyzed the reduction of oxygen (O2) in phosphate buffer solution (PBS). Practical application of Pt nanoparticle-doped s-BLM for the construction of glucose biosensor was also demonstrated in terms of its dose–response curve, stability and reproducibility. Thus, lipid membrane doped with Pt nanoparticles is a novel electrode system at nanoscale that can penetrate through the insulating membrane to probe molecular recognition and catalytic events at the lipid membrane–solution interface.