| Surface enhanced Raman scattering（SERS）is a spectroscopic technology with the advantages of high sensitivity,fast detection speed,nondestructive analysis and fewer samples required.Biosensors based on this technology have received extensive attention in recent years for detection of single molecules.SERS has been widely used for the characterization of materials and structures of substances,the analysis of the quantitative and qualitative detection of small molecules,proteins,and other substances.However,the detection sensitivity of biosensors based on surface-enhanced Raman spectroscopy still needs to be improved.Therefore,the development and designment of a substrate material with better enhancement effect is the basis for improving the detection ability of SERS biosensors to achieve sensitive detection of biomolecules.The detalied content in this article is as follows:1.Qualitative Study on the interaction between Nonivamide and Human Serum Albumin based on surface enhanced Raman spectroscopy and fluorescence spectroscopy.Under simulated physiological conditions,the interaction between Nonivamide（OC）and Human Serum Albumin（HSA）was based on SERS and fluorescence spectroscopy.Using Au NPs as the Raman substrate,the adsorption mode of OC on the surface of Au NPs was determined.SERS revealed that the phenolic group of OC combines with HSA and the influence of HSA on the adsorption mode of OC after recognition was analyzed.The thermodynamic parameters were calculated for the interaction between OC and HSA.The main binding force was hydrogen bonds and hydrophobic interaction force and the interaction was strong.The results of fluorescence spectroscopy indicated that OC slightly affected the secondary structure of HSA and increased the hydrophobicity of the microenvironment around the tryptophan residue.However,the conformation of OC did not change apparently with the addition of HSA.The information not only would be references to the study of the mechanism of the interaction between drugs and blood plasma or serum albumin but also a guidance to understand the metabolism of drugs in human body.2.A SERS biosensor based on the Silver nanowires substrate material for the sensitive detection of Nonivamide.At present,silver nanoparticles（AgNPs）has been attracting more and more attention because of excellent adsorption capacity and antibacterial activity.Silver nanowires（Ag Nws）not only have superior conductivity and controllable morphology,but also have a large specific surface area and specific volume.The unique optical,electrical and magnetic properties of Ag Nws can achieve the same enhancement effect as ordinary gold nanoparticles,and have better stability.SERS active substrate Ag Nws were prepared by a facile and effective two-step dropwise addition polyol method.In this study,a method for the detection of nonivamide（OC）was established.Ag Nws were chosen as SERS substrate to detect trace nonivamide and the SERS peaks were assigned.Under the optimized conditions,the linear regression equation was established between the concentrations of nonivamide residues（c）and the peak intensity（y）when the concentration range of nonivamide residues was 1-10-8 mg/L.And the detection limit of nonivamide was 0.66 pg/L.After the sample treatment,the recoveries were investigated by standard addition recovery method.This method had the advantages of short time,fast speed and low cost.It was expected to be developed as a common and fast method for the detection of nonivamide in heating agents.It layed the foundation for the subsequent use of SERS technology to achieve simultaneous detection of multiple components.3.A SERS biosensor based on metal organic framework combined with graphene oxide-silver nanocomposite materials for detection of myoglobin.Surface-enhanced Raman spectroscopy often uses a uniform and well-formed nanomaterial as a substrate to amplify the Raman signal.SERS biosensors are often used in the sensitive and specific detection of disease markers.In order to improve the sensitivity of the sensor,this study adopted that ZIF-67 worked as precursors for the preparation of cobalt nanoparticle doped porous cubic carbon（Co-PCC）materials with large specific surface area as well as thermal stability.In order to improve the sensitivity of the sensor,this study adopted the material with rich pore structure and high surface area combined with gold nanoparticles to as SERS substrate（Pt/Co-PCC）for sensitive detection of Myoglobin（MB）.Firstly,the SERS substrate Pt/Co-PCC was immobilized with primary antibody（Ab1）by covalent bond.Owing to the large specific surface area and good biocompatibility of Co-PCC,a large number of primary antibodies could be immobilized.Then the second antibody（Ab2）and Raman signal molecule crystal violet（CV）was fixated on graphene oxide-silver nanocomposite（GO-Ag）by adsorption.Due to the large specific surface area and high adsorption of GO,a large number of second antibodies and CV could be fixed.And due to the"hot spots"generated by silver nanoparticles,the Raman signal of CV can be obviously enhanced.With the presence of MB,for the specific binding capacity between antigen and antibody,the SERS signal part of the second antibody was immobilized on the magnetic material,thus realizing the detection of the target molecule.Finally,the sandwich immune complex was deposited on the surface of the hydrophobic material for experimentation to realize the detection of the target molecule.This study proved that the SERS-biosensor could be applied to the detection of MB with high sensitivity and low detection limit.The excellent performance also showed that this newly designed SERS sensor was expected to be used for ultra-sensitive detection of various disease markers,which offering a direction for rapid label free SERS analysis in the future. |
