Hand-powered POCT Devices For Malathion Detection

POCT(Point-of-care testing)plays an important role in alleviating the insufficiency of primary medical services and improving people’s living conditions.However,the fluid driving and mixing processes in POCT detection usually require electricity,and power supply becomes a critical issue in areas with imperfect power grids.Based on these,aimed at const ructing a POCT detection device that does not require electricity,this dissertation constructed hand-powered POCT devices that uses an easy-to-operate method to provide energy.This platform was validated based on the detection of malathion.Specific research contents are as follows:1.Manually mixed disposable centrifuge tubes for the detection of malathionAiming at solving the problem that the traditional POCT detection requires external electric drive.This work takes malathion detection as a model and builds a pesticide detection device that does not require electricity based on disposable centrifuge tubes.First,the acetylcholinesterase and indole acetate that using to detect malathion are embedded by pullulan and pre-stored in the bottom of the centrifuge tube and the cap of the centrifuge tube,respectively.When the sample solution is added to the centrifuge tube and the enzyme inhibition reaction occurs,close the cap of the centrifuge tube and shake to mix.By observing the color change of the solution,we can determine whether there is malathion contamination.The device is easy to operate,one only needs to add samples and shake to get the test results.The detection limit of malathion is 70 n M,and quantitative detection of malathion can be achieved in tap water samples.At the same time,the device has good selectivity for malathion.In addition,the device can get the test results within 30 minutes.This fast,simple,and sensitive pesticide detection method provides a powerful tool for foo d safety screening.2.Hand-powered centrifugal microfluidic chip for detection of malathion Although the above disposable centrifuge tubes were convenient to use,the detection throughput was low and only a single sample can be detected at once.In order to overcome this problem,this work built a manual centrifugal microfluidic platform that could detect multiple samples as needed.The device pre-stores acetylcholinesterase and indole acetate through the pullulan membrane in the enzyme inhibition reaction chamber and the color reaction chamber of the microfluidic chip respectively.After the sample was injected into the enzyme inhibition reaction chamber,enzyme inhibition occured.After that,the chip was placed on the dics,and the centrifugal force generated by the pulling dics transfered the solution in the enzyme inhibition reaction chamber to the color reaction chamber.After a period of time,by observing the color of the solution in the color reaction chamber,we could determine whether malathion is present.Multiple microfluidic chips could be placed on the platform’s dics as needed to achieve simultaneous detec tion of multiple samples or multiple targets.The detection limit of malathion is 0.1 μM,and quantitative detection of malathion in tap wat er can be achieved.In this dissertation,two hand-powered POCT detection devices are constructed,which is helpful for the rapid on-site detection of malathion.