Detection Of Novel Pollutants Based On SERS-nanozymes And Exploration Of Their Degradation Mechanis

Combining nanozymes and surface-enhanced Raman scattering（SERS）technology has significant advantages in environmental analysis.Nanozymes,artificial simulated enzymes,can be produced in large quantities,possess good ecological stability,and exhibit diverse activities.These superior properties make them highly promising for a wide range of applications.On the other hand,SERS technology is known for its ability to provide fingerprints,high detection sensitivity,and easy on-site non-destructive testing.By integrating these two technologies,we can effectively enhance the capabilities and depth of environmental analysis.As a kind of emerging contaminant,pharmaceutical and personal care products（PPCPs）have been widely used and posed serious risks to ecological systems,as their release into the environment can disrupt the human endocrine system,ultimately posing a serious threat to human health.Carbamazepine（CBZ）residues in water environments exhibit strong antibiotic degradation properties,making the detection and degradation treatment of CBZ in wastewater crucial for assessing water environment safety and ensuring human health.D-Penicillamine（D-PA）,as a thiol-containing drug,can cause various side effects through its excessive use,so monitoring the concentration of D-PA in water samples is of great significance for assessing water environment health.Ciprofloxacin（CIP）has been detected in different environmental matrices,and its excessive accumulation poses a substantial threat to the growth and reproduction of aquatic organisms.The presence of CIP also promotes the emergence,accumulation,and dissemination of antibiotic resistance genes,making it crucial to reduce CIP emissions.Ofloxacin（OFX）is considered an important pollutant in the ecological environment.Due to its high chemical stability,it is difficult to degrade OFX through biological treatment,making it particularly important to establish methods for the rapid detection and degradation of CIP.In this research,CBZ,D-PA,CIP and OFX were selected as typical PPCPs.Considering the complexity of water environments;we designed and synthesized highly sensitive nanozyme-SERS substrates to explore the potential of SERS sensors in the detection and degradation mechanism research of novel environmental pollutants.We achieved highly sensitive detection of these four pollutants and utilized the catalytic properties of nanozymes for their degradation.This research aligns with the development philosophy of green chemistry,providing new methods and technologies for the detection and degradation mechanism research of novel pollutants.This research includes the following four aspects:1)We synthesized multi-layered rose-like AuNPs/MoS₂ nanocomposites via a hydrothermal reaction.Using this composite nanomaterial,we achieved SERS detection of CBZ in wastewater with a detection limit of 1.36×10^-10mol/L and a linear range of 10^-9to 10^-3mol/L.Additionally,we found that the AuNPs/MoS₂ nanocomposites exhibited peroxidase-like activity,catalyzing the generation of ROS（·OH,O₂·-,and ¹O₂）from H₂O₂,thus achieving efficient oxidative degradation of CBZ in wastewater.Furthermore,the AuNPs/MoS₂nanocomposites can be recycled multiple times.This strategy provides a new approach and technology for effectively monitoring and degrading PPCPs in the environment.2)We utilized a hydrothermal method to further enhance the material performance to synthesize multilayered magnetic cobalt（Co）-doped AuNPs/MoS₂（Co）nanocomposites.The magnetic Co doping provided edge topological effects and enriched the active sites on the MoS₂nanosheets,facilitating the uniform loading of AuNPs.The ultrathin AuNPs/MoS₂（Co）maintained peroxidase-like activity.They catalyzed the oxidation of ortho-phenylenediamine（OPD）in the presence of H₂O₂,resulting in a characteristic new peak at 452 nm in the UV-visible absorption spectrum.Based on this peak,quantitative detection of OPD was achieved with a linear range of 10^-9to 10^-2mol/L.However,when the concentration of OPD was fixed,and D-penicillamine was added,we observed a continuous decrease in the UV-visible absorption intensity at 452 nm.This enabled highly sensitive detection of D-penicillamine with a linear range of 5 to 100 mmol/L,providing a convenient visual platform for the detection of D-penicillamine in the environment.3)Furthermore,for the convenience of sample pre-treatment,we also investigated magnetic nanoenzyme SERS substrates.We employed a hydrothermal method to synthesize AuNPs/Fe₃O₄NPs composite nanomaterials.A multifunctional SERS substrate was formed by combining AuNPs with strong surface-enhanced effects with magnetic Fe₃O₄NPs.The Fe₃O₄NPs played a role in magnetic enrichment and exhibited peroxidase-like activity.Based on the coordinated interaction between different components in this composite nanomaterial,we achieved highly sensitive SERS detection and efficient degradation of ciprofloxacin in wastewater,with a linear detection range of 10^-9to 10^-5mol/L.Similarly,AuNPs/Fe₃O₄NPs with peroxidase-like activity catalyzed the generation of ROS from H₂O₂,enabling efficient oxidative degradation of ciprofloxacin in wastewater,with a degradation efficiency of 89.5%within 45 minutes.This provides a feasible solution for effectively degrading emerging environmental pollutants such as ciprofloxacin in wastewater.4)Finally,we integrated magnetism,enzymatic activity,and SERS enhancement to prepare multifunctional AuNPs/Fe₃O₄NPs@MoS₂（Co）nanocomposites.The doping of Co not only endowed the MoS₂nanosheets with outstanding topological edge effects but also enhanced their catalytic activity.MoS₂（Co）provided a larger specific surface area,facilitating the loading of Fe₃O₄NPs and AuNPs.MoS₂（Co）loaded with Fe₃O₄NPs exhibited magnetic enrichment and enhanced peroxidase-like activity.The synergistic interaction among the components of AuNPs/Fe₃O₄NPs@MoS₂（Co）nanoenzymes enabled highly sensitive SERS detection and efficient degradation of ofloxacin in wastewater,with a linear detection range of 10^-9to 10^-5mol/L,achieving a degradation rate of 90.5%for OFX within 40 minutes.Within the framework of sustainable green development,the integration of multifunctional nanoenzymes with surface-enhanced Raman spectroscopy（SERS）technology enables highly sensitive and rapid detection of PPCPs（such as cefalexin,D-quinine,ciprofloxacin,ofloxacin,etc.）in the environment,while achieving their efficient degradation.This combination of technologies provides a promising solution for addressing the issue of antibiotic pollution in the environment,aligning with the principles of sustainable development.