Low Field Nuclear Magnetic Sensing Technology Based On Hydrogel-coated Superparamagnetic Particles

In recent years,with the gradual development of food safety sensor detection technology,efficient and fast detection methods have been highly respected.Low-field nuclear magnetic resonance technology has been widely used in the field of food safety testing as a convenient,non-destructive and fast detection technology.At the same time,as a detection system that can be widely used,the recognition ability of the system is also the key to determining the sensitivity of the sensor.Self-assembled hydrogels based on aptamers,because of their unique hybrid chain reaction technology,can accurately and sensitively identify targets,so self-assembled hydrogels as recognition elements have unlimited potential.Based on superparamagnetic nanoparticles,a responsive polyacrylamide hydrogel that can self-assemble by nucleic acid hairpin hybridization chain reaction was designed in this paper,and a universal low-field NMR sensing platform was successfully constructed.As the concentration of the detection target gradually increases,a hydrogel coating composed of an aptamer that can specifically bind to the target is opened layer by layer on the surface of the magnetic nanoparticle,resulting in a gradual increase in the exposure of the magnetic nanoparticle,thereby The low-field NMR signal changes.This method has the advantages of fast,convenient,low cost,easy operation and high repeatability.In this study,low-field nuclear magnetic sensing technology based on hydrogel-coated superparamagnetic particles was first used to achieve rapid detection of adenosine triphosphate(ATP).Since ATP is the product of cancer cell overexpression,this method can be used for cancer The rapid detection of cells in vitro has a good prospect in the medical field;this study went on to build a multifunctional low-field NMR sensing platform,and verified the versatility of the platform with PCB77.It is hoped to achieve the effect of detecting multiple targets only by replacing the aptamer of the target,which can be popularized for monitoring in the field of food safety.