A Novel Bioelectrochemical Sensor Based on Immobilized Urease on the Surface of Nickel Oxide Nanoparticle and Polypyrrole Composite Modified Pt Electrode

Abstract

Abstract Nickel oxide nanoparticle (NiO−NP) and polypyrrole (PPy) composite were deposited on a Pt electrode for fabrication of a urea biosensor. To develop the sensor, a thin film of PPy−NiO composite was deposited on a Pt substrate that serves as a matrix for the immobilization of enzyme. Urease was immobilized on the surface of Pt/PPy−NiO by a physical adsorption. The response of the fabricated electrode (Pt/PPy−NiO/Urs) towards urea was analyzed by chronoamperometry and cyclic voltammetry (CV) techniques. Electrochemical response of the bio‐electrode was significantly enhanced. This is due to electron transfer between Ni 2+ and Ni 3+ as the electro‐catalytic group and the reaction between polypyrrole and the urease‐liberated ammonium. The fabricated electrode showed reliable and demonstrated perfectly linear response (0.7–26.7 mM of urea concentration, R 2 = 0.993), with high sensitivity (0.153 mA mM −1 cm −2 ), low detection of limit (1.6 μM), long stability (10 weeks), and low response time (∼5 s). The developed biosensor was highly selective and obtained data were repeatable and reproduced using PPy‐NiO composite loaded with immobilized urease as urea biosensors.

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Identifiers

DOI

10.1002/elan.201800862

Journal

Electroanalysis

Year

2019