Covalent Immobilization of Glucose Oxidase onto Electro-synthesized Nanocomposite with PEDOT Derivative for Amperometric Glucose Biosensing

Abstract

A highly sensitive and specific glucose (Glu) amperometric biosensor was successfully developed by the covalent immobilization of glucose oxidase (GOx) onto the electro-synthesized ionic liquid (ILs) modified poly(3,4-ethylenedioxylthiophene) derivative poly(hydroxymethylated-3,4ethylenedioxylthiophene) (PEDOTM) nanocomposite based on multi-walled carbon nanotubes functionalized with carboxyl group (MWCNTs-COOH). A highly-stable and conducting PEDOTM was one-step electro-synthesized in water/ILs mixed system containing BmimPF 6 and MWCNTs-COOH , then GOx was covalently immobilized onto the biocompatible ILs modified PEDOTM-MWCNTs-COOH with high affinity, which was employed for amperometric biosensing of Glu in human urine, human and animal serum samples. IL/PEDOTM-MWCNTs-COOH displayed good electrochemical activity, excellent electrochemical stability and high conductivity. The fabricated GOx biosensor showed pronounced amperometric current toward Glu response in a wide linear range of 6.0×10-8 ～2×10-3 M with a high sensitivity of 89.5 μA M −1 cm −2 , rapid response time within 10 s, low limit of detection of 0.015 μM, remarkable biocompatibility and bioaffinity, high sensing stability, excellent selectivity and practicality. Satisfactory results reveal that the ILs-PEDOTM-MWCNTs-COOH will provide a promising biosensing platform for the covalent immobilization of biomacromolecules and disease diagnostics via the detection of Glu in human and animal serum samples.

A Conjugated Polymer and SWCNTs Transducer for an Effective Biosensing Tool

“…In this work, it was reported a good sensing ability sensor device was fabricated with the help of the carbon nanotube. 22 Similarly, a glucose biosensor combining of PtPd bimetallic nanoparticles with multi-walled carbon nanotubes (PtPd-MWCNTs) was examined by Hwang et al 23 In this work, the Michaelis-Menten constant (Km) was reported as 3.3 mM and the sensor was in actual serum samples with high accuracy. Aviles and coworkers were designed iron oxide nanoparticles decorating the surface of MWCNTs and used as a glucose sensing system.…”

Review—Carbon Nanotube-Based Electrochemical Glucose Biosensors

“…68 While for the immobilized GOx, the amperometric response slowly increases with increasing temperature and reaches a maximum value at the range of 35 °C-40 °C. 69 This is due to the good microenvironment provided for GOx by different CNT-based nanocomposites. The further increase of temperature over 40 °C, leads to a sharp decrease of current response, possibly due to the GOx denaturation.…”

Enzyme Immobilization and Optimization on Polymeric Nanospheres

“…Bölüm 2.5'de belirtildiği gibi, Lineaweaver-Burk grafiği, serbest ve immobilize GOx için tüm optimum koşullar da 1/S'ye karşı 1/V değerleri hesaplanarak çizildi. Bu grafiklerden Km ve Vmak kinetik değerleri aşağıda verilen formüle göre hesaplandı [11,12]. Bulunan değerler Tablo 3'de verildi.…”