Preparation Of A Composite SERS Substrate And Its Detection Of Cancer Markers

Cancer is a serious threat to human health and life.Early detection of tumor markers is an effective ways to improve the survival rate of cancer patients.Raman spectroscopy could provide molecular structure and substance composition information of test substances,which can judge structural differences between cancerous and normal tissue.Raman spectroscopy could achieve high sensitivity,high resolution and fast detection,which can be used for early diagnosis of cancer.According to literature,it shows that sarcosine can activate prostate cancer cells.And its detection in urine means the occurrence of malignant prostate cancer.As an important endogenous regulatory factor,cytidine plays a crucial role in the physiological activities of various tissues and organs.Cytidine is a potential biomarker for colon cancer.Quantitative detection of cytidine in human body can effectively monitor cancer.Sialic acid?N-acetylneuraminic acid?is a derivative of N-acetylneuraminic acid,which is elevated in various inflammatory diseases and malignant diseases.Such as lung cancer,gastric cancer,bowel cancer,liver cancer,ovarian cancer.At present,GC,MS,GC-MS and LC-MS have been used to test different samples.These traditional detection methods have good accuracy and reproducibility.They also have the disadvantages of complex sample preparation,large apparatus and low sensitivity,which make them unsuitable for on-site rapid analysis and detection.Surface-enhanced Raman scattering?SERS?spectroscopy overcomes these disadvantages.It provides structurally detailed molecular-level information and play an important role in the analytical detection of trace samples.An important aspect of surface-enhanced Raman spectroscopy is the preparation of SERS substrates that enhance Raman signals.Gold,silver nanoparticles often serve as SERS enhanced substrate.Magnetic materials have better enrichment and separation function,in the process of preparation of nanoparticles added to the magnetic nanoparticles can effectively improve the detection sensitivity.In this paper,a tentative study was conducted.It apply Raman spectroscopy to detect cancer markers,sialic acid,cytidine and sialic acid in urine.In order to establish a simple and rapid detection method of cancer markers,to further expand the scope of use Raman spectra for the development of disease detection in health for Raman spectroscopy.The main research contents and results are as follows:The biosensor of sarcosine in urine was determined by ?-mercaptoethylamine-linked gold and silver nanoparticles synthesized from bi-metallic SERS.The linear range was from 1.0 mmol/L to 50?mol/L?R²=0.9740?and the lowest detection concentration was 10^-88 M.The magnetic composite material was synthesized in situ by introducing ferroferric oxide magnetic material.The method has good stability and sensitivity,it is suitable for the detection cytidine in urine.The linear range of detection is 1.0×10^-4mol/L to 1.0×10^-33 mol/L,RSD is 0.7¹.3%.The introduction of mercaptophenylboronic acid modified in-situ reduction of magnetic gold nano-materials in the volatile serum to detect sialic acid.At alkali environment?pH=9.21?can achieve reversible detection of sialic acid in serum,the method is simple and quick.This study shows that using Raman spectroscopy could realize the detections of sarcosine,cytidine,and sialic acid with a certain degree of practical promotion value.As a fast,facile,non-destructive and sensitive technique,Raman spectroscopy has certain application prospect and market potential in disease diagnosis.