SERS Chip Based On Metal Organic Framework Compound And Its Application In Environmental Monitoring

In recent years,with the emergence of the term"portable sensor",a variety of sensing devices are combined with microfluidic paper-based materials to meet the requirements of trace monitoring of multiple objects in the field.Surface-enhanced Raman spectroscopy（SERS）,as an emerging detection method,has appeared in the public eye.It can detect single molecules and has ultra-high sensitivity,non-invasive detection ability and unique fingerprint effect,but it still faces challenges when applied to complex sample analysis.At present,SERS active material is no longer a plasma material with single function,and the introduction of multi-component composites makes the testing span of SERS reach several orders of magnitude.Meanwhile,low-cost,easily modified and widely sourced cellulose paper is one of the best choices for SERS base.Therefore,the construction of paper based SERS strips with multi-component enhancement factor is the key to optimize the real-time monitoring sensor.Aging behaviors are frequently observed in many kinds of materials,indicating the gradual changes of certain properties of materials with time elapsing.For ferroelectric materials,the aging behaviors mainly include the phenomena of double hysteresis loops and asymmetry of coercive field.（1）Based on the folding and assembly characteristics of paper fiber three-dimensional structure,controllability of metal-organic skeleton material and designability of plasma metal material form,a surface-enhanced Raman scattering（SERS）sensor was established for the rapid field determination of ethephon in food.HKUST-1（Cu）was assembled on the carbon treated chromatoscopic paper matrix by electrodeposition,and the bottleneck problem of poor affinity of SERS substrate to target molecules was overcome by its skeleton respiration and sponge effect.Combined with the targeting specificity of bionic antibody,a paper based interface with high molecular sensitivity specificity was constructed.A sandwich multistage progressive enhanced structure was designed to achieve superposition and collaborative amplification of SERS signal by in-situ coupling of plasma pine dendritic silver material at the interface.When paper bar sensors are used to monitor ethephon,the linear range is 10^-3 to10 mg·kg^-1,and the detection limit is about 1.39×10^-4 mg·kg^-1.The construction and application of paper-based HKUST-1（Cu）/BAs/PBSM sensor will provide technical means and theoretical support for rapid and efficient identification of biological maturing agent residues in food by multistage signal enhancement.（2）Based on the reusable SERS probe device,a SERS sensing paper strip with core@shell-satellite composite structure composed of silica core,silver shell and surrounding gold nanoparticles was constructed,which was used for trace monitoring of furtefuran in fruits and vegetables.Firstly,Si O₂@Ag core-shell material with high density plasma hot spot was modified on the amine-based paper fiber by impregnation strategy.Then,Au NPs were connected to the surface of Ag shell by crosslinking agent to form a stable structure of Ag shell-Au satellite,which realized the maximum utilization of laser in three-dimensional space and provided efficient SERS performance.At the same time,the material adsorped on the surface of paper fiber could be desorption into ethanol by ultrasound,achieving the purpose of material reuse,which provided a development prospect for low-cost SERS sensor strips.