Research On An Aptasensor For Organophosphorus Pesticide Detection

Organophosphorus pesticides refer to organic compound pesticides containing phosphorus.They are widely used to prevent and control plant diseases,insects,and grass diseases.Their residues are commonly found in rivers,lakes,and soil.Long-term exposure to the environment containing organic phosphorus,even at concentrations below 1 n M,may cause damage to the liver and central nervous system of humans and animals.The existing detection methods are not sensitive enough to detect trace amounts of organic phosphorus.An easy-to-use aptamer capacitive sensor is proposed,which can detect organic phosphorus with high sensitivity and fast.The DNA aptamer was used to modify the surface of the micro-finger electrode chip with good specificity.AC electrokinetics is used to accelerate the combination of organic phosphorus molecules and aptamer probes,and the detection time from the sample to the result is only 30 s.As a quantitative indicator of organophosphorus pesticide concentration through the super sensitive interface capacitance change rate,the aptamer sensor has a wide linear range of f M ?n M,and the detection limit of four highly toxic organophosphorus pesticides is as low as 0.24 ? 1.67 f M.At the same time,experiments have verified that the sensor has the same response law to a variety of actual pesticide samples,and the actual pesticide recovery rate is 83.6% ? 97.9%.Considering that pesticides are mixed in practical agricultural applications,the mixed samples of actual pesticides were tested to verify the same response law.In addition,the problem of decomposition of organic phosphorus molecules with increasing temperature was studied at different temperatures.Finally,the long-term effectiveness and recycling performance of the sensor have been studied and verified.The experimental results show that the sensor still shows good effectiveness after being stored at room temperature for at least 14 days,and has a reusable within a certain concentration range performance.In summary,the aptamer capacitive sensor studied and implemented for the simultaneous detection of four organophosphorus pesticides has many advantages such as low detection limit,short detection time,good specificity and easy storage.Pesticide on-site real-time detection provides a new and effective solution.