Study On Non-enzymatic Glucose Sensors Based On Screen Printing Techniques

Over the past few years,great attention has been paid to the development of electrochemical glucose sensors due to their advantages of low cost,high sensitivity and quick response.Reliable,rapid detection of the concentration of glucose is of greatly importance in many fields such as clinical diagnostics,biotechnology and food safety.The glucose sensors based on glucose oxidase(GOx)have been widely investigated owing to their high sensitivity,specificity and low detection limit.However,the activity of GOx is easily interferenced by factors such as temperature,humidity,pH and toxic chemicals.To overcome such drawbacks,glucose biosensors without enzymes have been researched.Most of the metals(Au,Pt,Cu,Ni),metal oxides(Cu2O,CuO,RuO2,NiO,ZnO),alloys(Pt–Pb,Au–Cu,Pt–Cu,Pt–Au,Cu-Ag,CuO-Ag)and metal/metal oxide-carbon composite materials(Au-carbon nanotubes,copper oxide-graphene)have been used to fabricate non-enzymatic glucose sensors.However,due to the shortcomings of material and electrodes,making the electrochemical properties and applications has been greatly restricted.CuO nanosheets and CuO-MWCNTs composite were produced by a facile and effective situ method.After dried and grinded,the powder were tuned into printing pastes and were printed in the graphite electrode and silver interdigitated electrode using a screen printing machine.Non-enzymatic glucose sensor prepared by the method has a fast response,high sensitivity,low detection limit,wide linear range,good stability.In this paper,the main work is as follows:Firstly,CuO nanosheets and CuO-MWCNTs composite were produced by a facile and effective situ method and were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray diffraction(XRD).The results demonstrated that the CuO nanosheet were connected by the MWCNTs to form uniform three-dimensionally(3D)-networks.The printing pastes were produced by CuO-MWCNTs powder,erpineol and ethyl cellulose at a suitable proportion.Secondly,nano silver paste were used to print silver interdigital electrodes on PET plastic.Based on graphite sheet and silver interdigital electrode,two different non-enzymatic glucose sensors were fabricated using CuO-MWCNTs paste.Thirdly,reaction mechanism,response time,sensitivity,detection limits of catalytic oxidation of glucose based on CuO-MWCNTs modified graphite electrodes,CuO-MWCNTs modified silver interdigital electrodes and silver interdigital electrodes were tested by cyclic voltammetry(CV)and chronoamperometry(I-t).The results demonstrated that both CuO and Ag can catalyze oxidation of glucose,and the use of CuO-MWCNTs modified silverinterdigital electrodes made of non-enzymatic glucose sensor than the graphite electrode has a higher sensitivity,faster response times,wider the linear range and lower detection limits.Lastly,the sensors have good anti-jamming performance for uric acid(UA),dopamine(DA),ascorbic acid(AA),sodium chloride(NaCl)and other substances.By detecting human serum samples,the sensor has a high recovery and good reproducibility.It has great potential value in future actual glucose detection.