Construction Of Hb/AuNPs/PPy/GCE Hydrogen Peroxide Sensor And Its Application

Hydrogen peroxide was widely used in industrial production,it also plays an important role in physiological reactions of the bodyand as an intermediate product of proteases such as glucose oxidase.However,excessive hydrogen peroxide emissions will seriously affect the ecological environment,in addition,residual hydrogen peroxide in food will not only reduce nutrition of food,but also harm the health of consumers.At present,hydrogen peroxide detection methods have some disadvantages with poor sensitivity and expensive instruments.Therefore,it's great significant of developing an economical,accurate and rapid method to detect hydrogen peroxide concentration in food processing and environmental protection.In this paper,polypyrrole and gold nanoparticles were modified to the electrode surface with electrochemical technology,and the Hb/AuNPs/Ppy/GCE sensor was prepared by combining the hemoglobin molecules with adsorption effect and covalent bond between nanoparticles and hemoglobin.The preparation conditions and detection parameters of the sensor were optimized,and the detection performance of the sensor was investigated.The main research contents are as follows:(1)The potentiostatic method was used to reduce pyrrole and form polypyrrole film on glassy carbon electrode.Then,the cyclic volammetry method was used to reduce chlorogold acid and deposit it on the substrate of the p.olypyrrole film.The physical and chemical characterization proved that the sensor was successfully prepared and had a good catalytic effect on hydrogen peroxide reduction.The DPV response current of the sensor in KCl solution containing 20 mol/L H2O2 as the evaluation index,optimizing preparation conditions and detection parameters of the sensor.The results showed that optimized parameters was:pyrrole polymerization amount 2.0×10-3 C,phosphate buffer solution pH of 6.5,supporting electrolyte KCl solution pH of 7.0,detection parameters of 0.2 pulse period and pulse width of 0.03.(2)Hb/AuNPs/Ppy/GCE sensor was prepared under the optimal conditions,and the selectivity,stability and reproducibility of the sensor were investigated.The results showed that the detection limit of the sensor was 0.2 mol/L.And presents a good anti-interference effect on the detection of hydrogen peroxide when the existing of dopamine,ascorbic acid and uric acid et.al.After being stored in the refrigerator at 4? for 14 days,the response current of Hb/AuNPs/Ppy/GCE was 88.3%of the initial current value,indicating that the sensor had good stability.Compared with other hydrogen peroxide sensors,this method is suitable for the detection of hydrogen peroxide.(3)Hb/AuNPs/Ppy/GCE sensors was used to detect hydrogen peroxide content in different water samples and milk samples.The results show that the standard addition recovery of sensor detection in different water samples of was 92%-102%,relative standard deviation was 3.2%,the milk samples of standard addition recovery was 86%-105%,relative standard deviation is 4.07%.These results show that the sensor can be used to detect the hydrogen peroxide of water and milk samples.