The Study On High Activity Photoelectric Materials And Their Applications In Biosensors

Diabetes is a worldwide disease with high prevalence,and it will cause metabolic disorders leading a series of complications.Then the life quality of patients will be significantly reduced.Therefore,the detection of diabetes is important in practical significance.In fact,blood glucose is an important index in the diagnosis of diabetes.Meanwhile,insulin detection will be able to type diabetes,and detection in gene level is more conducive to the prevention of diabetes.However,insulin detection and gene detection need to be processed by professionals in the hospital,which is not conducive to individual preliminary screening.Therefore,the sensitive biosensor toward diabetes is necessary.In this paper,the detection performances of the photochemical biosensors were improved by enhancing the material activities and optimizing the electrolyte,while the biosensors used to detect the indicators related to diabetes,including blood glucose,I27L gene and insulin was constructed.Then,the contents of each chapter are as follows:In second chapter,a mesoporous zinc oxide containing different concentrations of oxygen vacancies was controlled synthesized via low temperature annealing.XPS,Raman spectroscopy and electron paramagnetic resonance spectroscopy(EPR)were employed to investigate the changes of oxygen vacancies concentrations following the increase of annealing temperature.According to the result,increasing oxygen vacancies could result in higher carrier density,active sites and catalytic rate constant.Then the performance toward glucose detection could be improved by increasing oxygen vacancies.In third chapter,a novel method based on the competitive reaction of ascorbic acid(AA)was introduced for improving the performance of signal off photoelectrochemical glucose enzyme sensor.AA was regarded as not only the electron donor to capture the hole in the conduction band(CB)of Zn O,but also the remover of H₂O₂ produced by the oxidation of glucose.As a result,the stability of response current,detection ranges,detection limit and sensitivity were optimized prominently.In forth chapter,C-doping Zn O with oxygen vacancies is rationally prepared with the assistance of ascorbic acid.As C-dopants and oxygen vacancies could introduce acceptor and donor levels in Zn O,respectively,the intramolecular donor-acceptor compensated semiconductor Zn O(I-D/A Zn O)is successfully achieved.According to the DFT calculations,the donor-acceptor compensated semiconductor with the asymmetry DOS will lead to the long carrier lifetime and the small electron transfer resistance.Finally,a photoelectrochemical biosensor toward glucose based on the detection strategy discussed in third chapter was constructed using I-D/A Zn O and showed the good performances,suggesting that I-D/A Zn O is a promising semiconductor for photoelectrochemical biosensor.Meanwhile,including multi-defects is a powerful method to modulate band structure of Zn O,which lead to the excellent performance of Zn O.In fifth chapter,the excellent performances of C,N co-doped Zn O(C,N-Zn O)are predicted by theoretical calculation.And C,N-Zn O was prepared with the assistance with ZIF-8.I27L gene fragment was detected using the loop amplification strategy with the assistance of Exo?.Due to the well performance of C,N-Zn O and the high amplification efficiency of loop amplification strategy,the electrode shows the good performance toward DNA detection.At last,we prove that the strategy is universal.In sixth chapter,the strategy was established based on the strategy given in Chapter5,then the concentration of insulin was detection.As a result,it showed a good perfrmances.According to all the experiment,two empirical conclusions should be obtained:1)Optimization of electrode materials and electrolyte composition is one of the effective methods for improving the performance of biosensor,and this method is of universality,which can provide another effective path for the research of biosensor;2)multi-doping with non-metallic is an effective way to improve the photoelectric properties of Zn O,which could bring forth useful insights for the researching of metal oxide semiconductor.