The Study On Non-enzymatic Glucose Sensor Modified By Nano Copper

Diabetes is a serious threat to human beings' health.Enzyme glucose sensors have brought the gospel to mankind in the past few decades.At present,there are still some defects in the enzyme sensor,such as enzyme deficiency,repeated stability and poor storage stability,and be vulnerable to external noise interference.More and more attention has been paid to non-enzymatic sensors because non-enzymatic sensors can overcome these shortcomings.This paper prepared ITO electrodes modified by nano copper and nickel using an electrochemical method with ITO electrodes as the substrate in order to detect monosaccharide(glucose and fructose)and disaccharides(lactose,maltose and sucrose).The results showed that the Cu/Ni/ITO electrode had a good sensitivity to monosaccharide and disaccharide,and the detection sensitivity of monosaccharide was higher than disaccharide.The detection principle can be summarized as follows: The aldehyde groups were converted to carboxylic acid under the catalytic oxidation of the electrode which lead to the change of electrode surface conductivity and oxidation peak.Although fructose is not glucose,but it is the isomer of glucose,which can be converted to glucose in alkaline environment.Disaccharide can also be detected because the isomerization reaction of disaccharide in alkaline environment can produce aldehyde group.Further experiment showed that the size and morphology of nanoparticles affected detection performance.Used Au-Pd composite film ITO electrode prepared by magnetron sputtering as the substrate,and then deposited copper nanoparticles on Au-Pd composite film ITO electrode to prepare the Cu/Au-Pd/ITO electrode by electrochemical method.Glucose detection by Cu/Au-Pd/ITO electrode was significantly better than Cu/ITO and Au-Pd/ITO electrodes.The sensitivity and the response current intensity were obviously improved,and the response current was linearly correlated with the glucose concentration.The morphology analysis showed that the Cu/Au-Pd/ITO electrode had smaller particle size,more uniform distribution of unit area and better detection performance than other electrodes.The cyclic voltammetry curves showed that the redox potential of Cu/Au-Pd/ITO electrode closer to 0 V.The results showed that the interface between nano copper and nano Au-Pd can enhance the catalytic activity.It was of great significance to develop non-enzymatic glucose sensor with low driving voltage.