The Electrochemical Study On Determination Of Deoxyribonucleic Acid

Deoxyribonucleic acid (DNA) is both the main chemical component of chromosomes and the composition of genetic material.The determination of Deoxyribonucleic acid is an important topic in life science, clinical examination, biochemical studies, and environmental science. In this dissertation, deoxyribonucleic acid is studied by the electrochemistry examination on the hanging mercury drop electrode(HMDE)and activated glassy carbon electrode(AGCE).It is discussed that the preparation method of the electrode and the optimal detection conditions. The interaction between p-nitrophenol and DNA is also studied by the electrochemistry, and develop a method which use p-nitrophenol as electrochemical probe to determine DNA. The main results are expressed as followed:1.Expounded the challenges of determination of DNA to electroanalysis chemistry, and summarized the state of deoxyribonucleic acid by electrochemical method.2.In Britton-Robinson buffer solution, use differential pulse stripping voltammetric (DPSV) to determine DNA on hanging mercury drop electrode which use malachite green as electrochemical probe. The determination conditions of pH, supporting electrolyte, accumulation potential, accumulation time, and voltammetric response were optimized. The ip decreases were linear over the DNA concentration range of 4μg mL-1～120μg mL"1 with a detection limit of 1.43μg mL-1 and relative standard deviations of 2.65～4.33% were observed in the best condition. The proposed method was applied to the determination of DNA in synthetic samples with recovery range of 96.0%～106.5%.3.The preparation of activated glassy carbon electrode (AGCE) in NaOH solution and its electrocatalytic reduction for DNA was studied.It is indicated that DNA could have a better limit of detection and liner range by linear scan voltammetry in Britton-Robinson buffer solution. Actived glassy carbon electrode had good stability and adapted to a series of determination. Under the optimum conditions, the ip were linear over the DNA concentration range of 2.5μg mL-1～200μg mL-1 with a detection limit of 0.184μg mL-1 and relative standard deviations of 2.24～4.43%.The proposed method was applied to the determination of DNA in samples with recovery range of 97.4%-104.9%.4. The interaction between p-nitrophenol and DNA was studied on glassy carbon electrode, it was calculated that t he binding ratio of p-NP:DNA was 2:3 and the binding constant was 7.4×106.The conditions for the interaction were optimized. Under the optimal conditions, the ip of p-nitrophenol decreases were linear over the DNA concentration, and develop method to determine DNA which use p-nitrophenol as electrochemical probe, and applied in the determination of DNA samples. Under the optimum conditions, the ip decreases were linear over the DNA concentration range of 1.0μg mL-～50μg mL-1 with a detection limit of 0.21μg mL-1 and relative standard deviations of 2.43～4.16%.The proposed method was applied to the determination of DNA in synthetic samples with recovery range of 96.4%～104.9%.