Synthesis Of Metal Based DNA Hybridization Indicator And Their Sensing Application

Deoxyribonucleic acid(DNA)is the carriers of hereditary information in lives.The interaction of metal complexes and DNA has roused extensive attention.Electrochemical gene biosensor is a new detection technique of gene in the fields of molecule biology investigation.It has been widely used in the fields of life sciences,medical science and drug screening owing to advantages of good-selectivity,simplicity,rapid and good sensitivity,et al.Metal complex-based indicators are series of promising indicators,which have the advantages of easy synthesis process,abundant kinds,sensitive optical and electrochemical signals and controllable function modification,et al.Therefore,they have been widely used in DNA electrochemical biosensors.In this paper,several electrically neutral metal complexes were synthesized,which greatly weakened its non-specific electrostatic interaction with ssDNA,and thereby enhanced the recognition ability to ssDNA and dsDNA.Some neutral metal complexes were used as hybridization indicators in electrochemical detection of gene fragments.The main work includes:(1)The complexes of Co(GA)2(phen)(phen=1,10-phenanthroline,GA=glycollic acid);Mn(phen)(PC)(H2O)[PC=2,6-pyridyl-(carboxylic)2];Cu(phen)(PC)(H2O);Schiffs base copper complex CuL(L= Schiffs base)were synthesized.The molecular structures and electrochemical properties of these complexes were characterized by X-ray diffraction analysis,Fourier transform infrared spectrometry,and electrochemistry,et al.(2)The electrochemical properties and mechanism of the electrically neutral metal complexes were obtained by several electrochemical methods.The interactions of the metal complex with DNA in solution were studied.The binding constant,binding site,and electrochemical parameters such as electron transfer coefficient and electron transfer rate constant were also obtained by electrochemical methods.(3)The dsDNA and ssDNA modified electrodes were prepared by covalent immobilization method,and were used to study the different interactions with the metal complexes.The binding mechanism,binding parameters and electrochemical data were also obtained by this micromethod.(4)The gene probes were immobilized at the electrode by covalent binding or physical adsorption,resulting in electrochemical gene biosensors.Co(GA)2(phen),Mn(phen)(PC)(H2O),Cu(phen)(PC)(H2O)and CuL were used as electroactive hybridization indicators to detect the target sequences,and obtained good selectivity and linear range.The complete detection technologies of electrochemical DNA were fabricated.