Highly Sensitive Glucose Sensor Based on Pt Nanoparticle/Polyaniline Hydrogel Heterostructures

TLDR

Glucose enzyme biosensors are useful for medical diagnosis, bioprocess monitoring, beverage industry, and environmental monitoring. We present a highly sensitive glucose enzyme sensor based on Pt nanoparticle/Polyaniline hydrogel heterostructures. High‑density Pt nanoparticles are homogeneously loaded onto a 3‑D PAni hydrogel matrix, combining conductive hydrogel and catalytic nanoparticles; the porous hydrogel facilitates enzyme immobilization and molecule penetration, enabling efficient glucose oxidation and H₂O₂ decomposition, with charges collected by the conductive heterostructure. The sensor achieved unprecedented sensitivity of 96.1 µA mM⁻¹ cm⁻², a 3‑s response time, a linear range of 0.01–8 mM, and a 0.7 µM detection limit.

Abstract

Glucose enzyme biosensors have been shown useful for a range of applications from medical diagnosis, bioprocess monitoring, to beverage industry and environmental monitoring. We present here a highly sensitive glucose enzyme sensor based on Pt nanoparticles (PtNPs)-polyaniline (PAni) hydrogel heterostructures. High-density PtNPs were homogeneously loaded onto the three-dimensional (3D) nanostructured matrix of the PAni hydrogel. The PtNP/PAni hydrogel heterostructure-based glucose sensor synergizes the advantages of both the conducting hydrogel and the nanoparticle catalyst. The porous structure of the PAni hydrogel favored the high density immobilization of the enzyme and the penetration of water-soluble molecules, which helped efficiently catalyze the oxidation of glucose. In addition, the PtNPs catalyzed the decomposition of hydrogen peroxide that was generated during the enzymatic reaction. The transferred charges from these electrochemical processes were efficiently collected by the highly conducting PtNP/PAni hydrogel heterostructures. The glucose enzyme sensor based on this heterostructure exhibited unprecedented sensitivity, as high as 96.1 μA·mM(-1)·cm(-2), with a response time as fast as 3 s, a linear range of 0.01 to 8 mM, and a low detection limit of 0.7 μM.