Research On ATP Detection Method Based On Aptamer And Nucleic Acid Self-assembly Structure

As a kind of high energy phosphate compound,ATP widely exists in various organisms and participates in various important physiological and biochemical activities.The realization of ATP detection will be of great help to our study about various life activities.Now,many researches have been carried out on the detection method of ATP,and higher and higher requirements have been put forward for the speed and sensitivity of the sensors.In this paper,based on the self-assembly structure of nucleic acid,a biosensor utilizing electrochemistry and aptamer was designed for the detection of ATP.In this experiment,the tetrahedral structure will respond to ATP in the presence of it,resulting in configuration changes to form G-quadruplex,which will be converted into electrical signals by electrochemical platform to realize highly sensitive detection of ATP.Firstly,four well-designed sequences were used to synthesize tetrahedral structures,one of them was designed with ATP aptamer and the other one was designed with part of G-quadruplex sequences which were used for signal generation.The electrode was then incubated with the ATP and hemin.In the presence of ATP,on the one hand,the aptamer will combine with ATP which will shorten the distance between the two ends of the tetrahedron.On the other hand,the two parts of the G-quadruplex will combine with each other due to the construction change of the tetrahedral which resulting in the formation of the G-quadruplex.The resistance of the electrode surface will change significantly due to the reaction of hemin entering the G-quadruplex.Then through differential pulse voltammetry?DPV?scanning,obvious signal changes will be observed.When the ATP is not present,there is no signal change because the two parts of the G-quadruplex are far away from each other and will not react with each other.In order to get a better detection result,the sequence bases are optimized first.Then sequence concentration,hemin concentration,incubation time of MCH,incubation time after adding hemin and target were also optimized.Under optimal conditions,the statics reveals a good linear relationship between the peak current and the concentration of ATP in the range from 0.7 nmol?L^-1 to 70 nmol?L^-1.The detection limit is estimated to be 50pmol?L^-1.Through the specific experiment of the analogs of ATP,it was found that the sensor has good specificity for ATP.Finally,the designed sensor was used for the detection of real samples.Human serum and lake water samples were selected for detection.Good detection results have been obtained,indicating that the designed biosensor has a good application prospect in medical detection and environmental monitoring.