Electrochemical Biosensing Platforms Using Platinum Nanoparticles and Carbon Nanotubes

TLDR

The study aims to develop electrochemical sensors with enhanced hydrogen peroxide sensitivity by integrating 2–3 nm platinum nanoparticles with single‑wall carbon nanotubes. The sensors were fabricated by dispersing Pt nanoparticles in Nafion‑solubilized SWCNTs to form a conductive network on glassy‑carbon or carbon‑fiber electrodes, and a glucose‑oxidase‑based microelectrode was constructed to further improve glucose detection. TEM, AFM, and cyclic voltammetry confirmed Pt nanoparticle deposition and electrical contact via SWCNTs, and the resulting biosensor achieved a 3‑second response time with a 0.5 µM detection limit, outperforming electrodes modified with Pt or CNTs alone.

Abstract

Platinum nanoparticles with a diameter of 2-3 nm were prepared and used in combination with single-wall carbon nanotubes (SWCNTs) for fabricating electrochemical sensors with remarkably improved sensitivity toward hydrogen peroxide. Nafion, a perfluorosulfonated polymer, was used to solubilize SWCNTs and also displayed strong interactions with Pt nanoparticles to form a network that connected Pt nanoparticles to the electrode surface. TEM and AFM micrographs illustrated the deposition of Pt nanoparticles on carbon nanotubes whereas cyclic voltammetry confirmed an electrical contact through SWCNTs between Pt nanoparticles and the glassy carbon (GC) or carbon fiber backing. With glucose oxidase (GOx) as an enzyme model, we constructed a GC or carbon fiber microelectrode-based biosensor that responds even more sensitively to glucose than the GC/GOx electrode modified by Pt nanoparticles or CNTs alone. The response time and detection limit (S/N = 3) of this biosensor was determined to be 3 s and 0.5 microM, respectively.