Covalent Immobilization Of Glucose Oxidase Onto Electro-Synthesized Nanocomposite With Pedot Derivative For Amperometric Glucose Biosensing

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(hydroxym ethyl ated-3,4-ethylenedioxylthiophene) (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 6.0x10(-8) similar to 2x10(-3) M with a high sensitivity of 89.5 mu A M-1 cm(-2), rapid response time within 10 s, low limit of detection of 0.015 mu M, 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.