Research On Molecular Imprinting Sensing For Microcvstin-LR In Water

In the past few decades, industrial production, agricultural development and human activities disrupted the water system balance and brought water eutrophication. Water bloom occurred more and more frequently. As water bloom occurs, some algae produce harmful toxins. Among those toxins, microcystins-LR is the most harmful one. It is one cyclic peptide and poisonous. It is very stable and cannot be degraded by daily water treatment. So microcystin-LR is an important detection index in water quality monitoring. But now it lacks one efficient method to detect and monitor microcystin-LR.Molecular imprinting technology is one artificial molecular recognition method. The synthetic molecular imprinted polymers have the affinity and specificity like antibody. And they are very stable and cheap. Molecular imprinting technology is one ideal method, and can be used in microcystin-LR detection.In this study, we design and synthetize molecular imprinted film for microcystin-LR. To test the performance of the film, we use quartz crystal microbalance sensor and surface plasmon resonance sensor. Through modification of the film, we get two biosensors for microcystin-LR.By testing the quartz crystal microbalance-molecular imprinted film biosensor, the result indicated that our film was better than previous study with60%improvement while the20MHz QCM chip provides four-fold higher response than the10MHz one. The limit of detection of the biosensor was4×10-5mg/L which is lower than the safety guideline level of drinking water in China. The low sensor response to other analogues indicated the high specificity of the sensor to MC-LR. The sensor showed high stability and low signal variation less than2.58%after regeneration. The lake water sample analysis shows the sensor is possible for practical use.By testing the surface plasmon resonance-molecular imprinted film biosensor, the result indicted that the sensor was sensitivity to microcystin-LR with the range of dynamic measure of2.1x10-3～l mg/L. And the sensor did not have obvious response to microcystin-RR, the analogues of microcystin-LR, so the sensor had a good selectivity for recognition of microcystin-LR.The results indicate that the biosensors we built give a well-performed method to detect microcystin-LR under different situations. It provides a good candidate for environment water detection and drinking water safety.