Mediator-free amperometric glucose biosensor based on glucose oxidase entrapped in poly(vinyl alcohol) matrix

Abstract

A simple and novel amperometric biosensor for glucose detection is proposed. It is based on the immobilization of glucose oxidase (GOx) in a poly(vinyl alcohol) (PVA) matrix directly drop casted on a platinum electrode surface (Pt/GOx-PVA). Glucose was determined in the absence of a mediator used to transfer electrons between the electrode and the enzyme. The correlation between peak current (i(p)) and scan rate has been verified and the effect of pH solution has been checked. Glucose detection has been performed amperometrically at -400 mV by using pulsed amperometric detection (PAD). Under the selected optimal conditions, the biosensor showed low detection limit (10 μM), wide dynamic range (0.1-37 mM) and high sensitivity. The biosensor amperometric response revealed it to be specific to glucose without significant interference from other sugars and electroactive species coexisting with glucose in biological fluids. Response stability was another interesting feature of the developed system as it was almost completely recovered when the biosensor was left in opportune storage conditions (i.e., a response decrease of only 13% after 35 days in air at room temperature). Finally, X-Ray Photoelectron Spectroscopy (XPS) characterization revealed a homogeneous film deposited on the Pt substrate whose structure is also preserved under operative conditions.

Development and characterization of a novel bioactive polymer with antibacterial and lysozyme‐like activity

“…23 Briefly 3mg of GOx were dissolved in 1 mL aqueous solution containing 10% PVA in ultrasonic bath for 5 23 Briefly 3mg of GOx were dissolved in 1 mL aqueous solution containing 10% PVA in ultrasonic bath for 5…”

“…The UV absorption band at 275 nm is assigned to polypeptide chains in protein structure. [22][23][24]30 PVA is in fact considered an ideal enzyme immobilization material since its water content matches that of biological tissue. 46,47 The similarity of PVA-GOx solution and PVA-GOx film spectra suggests that PVA entrapment upon solvent evaporation does not determine any modification of enzyme structure in the dry polymer-embedded state.…”

“…22,23 It has been in fact widely used because of its inherent good biocompatibility and desirable physical properties, such as elastic nature and good filmforming properties. PVA represents an ideal enzyme immobilization material due to the abundance of hydroxyl groups providing a microenvironment similar to the enzyme's natural environment.…”

Measurements and predictive modeling of water diffusion coefficients in bovine serum albumin/polymer blends for biosensors

“…[1][2][3][4] In disposable biosensors, often a mixture of different polymers and other additives is employed. In these diagnostic devices, an active enzyme is entrapped in a polymer matrix for immobilization.…”

Influence of Poly(Vinyl Alcohol) (PVA) on the Cyclic-Voltammetry Behavior of Single-Crystal Pt Surfaces in Aqueous H2SO4

“…2 Poly(vinyl alcohol) (PVA) is a water-soluble hydrophilic polymer and has been employed in different applications. 3 It reacts with metal salts in aqueous solution leading to a metal chelate, being then usually selected as an ion and cluster capping agent to prevent excessive nanoparticle growth. [4][5][6][7][8] The mechanism of protection involves donation of the -OH lone electron pairs to the metals and prevention of aggregation through steric effect.…”