Fabrication Of Novel SERS Substrates And Its Application In Detection Of Heavy Metals And Aromatics Hydrocarbons

The presence of heavy metals and aromatic hydrocarbons in water will cause great pollution to the environment,and at the same time,it will also pose a risk to human life and health.The traditional analytical methods are characterized by cumbersome operation and long analysis cycle,which cannot meet the analytical needs of rapid in-situ detection.Surface Enhanced Raman（SERS）,as a new analytical and detection technology,has the characteristics of simple operation,rapid determination,high sensitivity and strong specificity,etc.,and has been widely used in biosensor,environmental science and food analysis and other related fields.The controllable preparation and performance regulation of SERS substrate is a hot issue in the SERS research field.However,due to the weak binding force of heavy metals,aromatic hydrocarbon molecules and noble metal nanomaterials,it is difficult to directly analyze and detect them by SERS technology.Based on this,this paper constructed two kinds of highly sensitive and specific SERS substrate materials and applied them to the analysis and detection of heavy metals and aromatic hydrocarbons.The main research contents are as follows:（1）Analysis and detection of zinc ions based on colorimetric/fluorescent/SERS tri-modal nanoprobe.Because of the complex detection environment and poor selectivity of detection and sensing,the detection results of metal ions in complex media are usually not ideal,so the accurate and selective field detection of metal ions has been widely concerned.In this chapter,we develop a three-mode sensing SERS nanoprobe for detecting Zn²⁺in environmental water samples.Inthisprobe,N-[6-piperazinyl-2-pyridyl]-N-（2-pyridylmethyl）-2-pyridylmethylamine dithiocarbamates（DPY）was self-assembled and modified on the surface of gold nanorods（GNRs-DPY）.After Zn²⁺ions were added to the self-assembled GNRs-DPY probe,the presence of Zn²⁺triggered the aggregation of GNRs-DPY,which increased the color and fluorescence intensity of the sensing system,and the detection limit of fluorescence was 3×10^-3μM.In addition,the strong electromagnetic enhancement between GNRs"hot spots"in the process of GNRs-DPY self-aggregation caused by Zn²⁺reduced the SERS detection limit to 6×10^-3 p M.It is worth noting that the sensing platform based on GNRs-DPY can not only distinguish Zn²⁺from Cd²⁺simply and quickly,but also be used as a three-mode nanoprobe for sensitive and selective quantitative determination of Zn²⁺in different substrates.Therefore,GNRs-DPY probe provides a new strategy for accurate and reliable field determination of Zn²⁺in complex samples,and has potential application value in medical point monitoring.（2）Rapid detection of p-aminophenol based on MOF loaded precious metal nanomaterials.It is important to design and accurately control the structure of metal-organic framework（MOF）at the molecular level for its properties and applications.In this chapter,an electrochemical synthesis method of gold nanoparticle supported MOF（Au@MOFs）composites is developed.By changing the deposition voltage and deposition time,the precise synthesis and regulation of the microstructure of the matrix materials can be realized.In this chapter,we have successfully prepared three kinds of Au@MOFs materials with unique morphology and size,they are Au@Cu-BTC,Au@Cu-BDC and Au@ZIF-8.Au@MOFs nanocomposite material combined the stable SERS"hot spots"provided by high density Au NPs and the excellent adsorption performance of MOF,which could effectively enrich the analyte near these"hot spots"and improve the sensitivity of SERS measurement value,and it could still detect 4-aminophenol（ATP）at the concentration as low as 10 n M.At the same time,MOF material is also a good catalytic material,and the doping of noble metal nanoparticles improves the catalytic capacity and increases the catalytic capacity for H₂O₂.This study not only provides a new method for customizing MOF based SERS substrate,but also shows that electrochemical deposition method has a good application prospect in the precise control of the morphology and structure of porous crystal composites.