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Construction Of SERS Biosensor With High Performance Micro-Nano Structure And Application In Disease Markers Detection

Posted on:2023-08-28Degree:MasterType:Thesis
Country:ChinaCandidate:P LiFull Text:PDF
GTID:2544307046994629Subject:Drug Analysis
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Simultaneous,sensitive and quantitative detection of disease markers is crucial for guiding treatment and predicting prognosis of malignant diseases.Compared with the detection of single-component disease markers,the simultaneous detection of multi-component disease markers has great research significance for improving the accuracy of early diagnosis and screening of diseases.In this thesis,two high-performance Surface-enhanced Raman scattering biosensors with micro-nano structures were constructed for simultaneous,accurate,and quantitative detection of multicomponent biomarkers in sepsis and liver cancer.The main research contents include:(1)In the first chapter,we introduced the importance of disease markers detection and simultaneous detection of multi-component markers in infectious diseases and liver cancer.Then,the common techniques used in the detection of disease markers and their limitations were analyzed,and introduce the advantages of SERS in the detection of multi-component disease markers and the application of protein and mi RNA disease markers.Finally,the research ideas of this thesis were proposed.(2)In the second chapter,a magnetically assisted SERS biosensor was developed for simultaneous,ultra-sensitive and quantitative detection of three inflammatory markers(IMs)in sepsis.Firstly,Ag-coated magnetic nanoparticles(Ag MNPs)embedded with the internal standard molecule 4-mercaptobenzonitrile(MBN)were synthesized as magnetic capture substrate with SERS enhancement and magnetic enrichment.Then,a highly SERS enhanced Au-Ag core/porous shell(CPS)structure was synthesized and modified with different Raman reporting molecules(Ra Rs)to form SERS tags.The aptamers or antibodies of the markers were modified on the surfaces of SERS tags and magnetic substrate,respectively,to specifically recognize the corresponding markers and form Ag MNPs/IMs/CPS sandwich structure.Finally,the multifunctional SERS sensor was used for the detection of three markers in sepsis(CRP,PCT and IL-6).The results indicated that the Raman signal intensity showed a good and wide linear relationship compared with IRa Rs/IIS and Lg CIMs,which could realize the simultaneous,accurate and quantitative detection of the three markers in serum.The limits of detection(LOD)for CRP,IL-6 and PCT were 102 fg/m L,10-1fg/m L and 1.0 fg/m L respectively.The results obtained by SERS method were basically consistent with those obtained in hospital,and this method can achieve multi-component detection.This method provides a sensitive sensing platform for rapid screening,accurate evaluation and diagnosis of acute infection and sepsis.(3)In the third chapter,We presented a nanoarray-based SERS biosensor combined catalytic hairpin assembly(CHA)with aptamer competitive strategy for simultaneous,ultrasensitive and quantitative detection of liver cancer markers AFP and mi R-375.Firstly,gold nanoarrays with uniform distribution of nanoparticles were synthesized.By modifying Au@Ag NPs on its surface,nanoarrays with high SERS enhanced performance were prepared.Hairpin structures Cy3-H1 and SH-H2 were designed according to mi R-375 and CHA strategy.The CHA strategy was used to amplify the signal of mi R-375 to achieve highly sensitive detection.Rox-Blocker sequences complementary to AFP aptamer were designed.Due to the presence of complementary sequences on H2,when AFP binds to aptamers,the Blocker was released and binded to H2,and Raman signals of Rox were detected.Simultaneous detection of mi R-375 and AFP was realized through CHA combined with aptamer competition strategy.The detected Raman signal intensity ratio showed a good linear relationship with Lg C,which could be used for ultra-sensitive detection of serum markers.The detection limits of AFP and mi R-375 were 10-3 ng/m L and 10-1 f M,respectively.SERS biosensor was applied to simultaneous detection of AFP and mi R-375 in serum of patients with liver cancer.The method is expected to be further applied to the ultrasensitive detection of other disease biomarkers in human blood.(4)The fourth chapter summarized the research contents of this thesis main innovation points,and prospects for the follow-up work.
Keywords/Search Tags:Surface-enhanced Raman scattering, Disease markers, Internal standard analysis, High performance SERS probe
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