Preparation Of Selective Catalytic Conductive Hydrogel Electrode Membrane In The Surface Layer Glucose Cell For Implantable Low Power Devices Application

With the development of low power implanted devices,the long-term,stable power supply to the implanted devices became a top research topic in recent years.The implantable abiotically catalysed glucose fuel cells is a feasible way to solve the problem of power supply in the body.The perfect implanted glucose fuel cell has the character,which includes the simple structure,high energy density,long-term stability and biological security.This topic is about the surface layer glucose cell for implantable low power devices application.In order to realize the selective glucose oxidation of anode in oxygen-rich condition,by using carbon nanotubes,nano platinum and hydrogel as base material,three kinds of conductive hydrogel anode were prepared.The nano-platinum conductive hydrogel application of theory basis and experimental basis about the surface layer glucose cell for implantable low power devices were provided.The research work and the results are as follows:In this paper,MWCNTs/PVA conductive hydrogel electrode membrane was prepared by using electropHoretic deposition(EPD)and freezing-thawing technology.The electrode membrane has high electrical activity area and low surface charge transfer resistance,high hydropHilicity and low mass transport resistance.The electrode membrane coated GCE showed the excellent electrocatalytic activity towards glucose electrochemical oxidation in the alkaline solution.It also showed the excellent electrocatalytic activity to dopamine in PBS solution.This investigation describes an effective strategy to fabricate an electrochemically active hybrid hydrogel made from PtNPs that are highly dense,uniformLy dispersed and tightly embeded throughout the conducting hydrogel network for the electrochemical oxidation of glucose.MWCNTs and PVA aqueous suspension was coated on GCE by electropHoretic deposition,and then pHysically crosslinked to form a three dimensional porous conductive hydrogel network by a process of freezing and thawing.The network offered 3D interconnected mass-transport channels and confined nanotemplates for in-situ growth of uniform platinum nanoparticles via the moderate reduction agent VC.The resulting hybrid hydrogel electrode membrane demonstrates an effective method for loading platinum nanoparticles on multiwalled carbon nanotubes by the electrostatic adsorption between multiwalled carbon nanotubes and platinum ions within porous hydrogel network.The hybrid hydrogel electrode membrane coated glassy carbon electrode showed excellent electrocatalytic activity and good long-term stability towards glucose electrochemical oxidation.The glucose oxidation current remained a linear relationship with the concentration of glucose in the presence of chloride ions,promising for potential applications of implantable bio fuel cells,biosensors and electronic devices.Since glucose and oxygen are simultaneously present in body fluids,the electrode reactions of anode are required to avoid mixed electrode potentials in implantable glucose fuel cell.Based on the different concentration between glucose and oxygen in body fluids,we took advantage of the catalytic activity of PtNPs,the current collector of MWCNts and the diffusion restriction of BC to design a conductive hydrogel electrode membrane,which can make the electrode reactions of anode be dominated by the glucose oxidation in oxygen-rich pHospHate buffered solution.The conductive hydrogel electrode membrane was prepared through a combined approach of the EPD treatment and the in-situ synthesis.That has a laminated structure with three dimensional nanopores,whose structure that resembles the Raney-type platinum,but the conductive hydrogel electrode membrane has the higher oxygen tolerance than the Raney-type platinum.We utilized the PtNPs/MWCNTs/BC electrode membrane as the anode and the MWCNTs/BC as the cathode to build the surface layer glucose cell for implantable low power devices application.Even in the case of the MWCNTs/BC cathode with very limited catalytic activity,the performance of fuel cell is close to the implantable Raney-type platinum fuel cell.Especially the conductive hydrogel electrode membrane has the same excellent biocompatibility as BC.The study showed that the PtNPs/MWCNTs/BC as electrode membrane of the surface layer glucose cell for implantable low power devices was feasible.The surface modification of PtNPs/MWCNTs/BC can not only improve the biocompatibility of the implanted devices,but also can provide electrical energy supply for the implanted devices.