Enzyme-amplified SERS immunoassay with Ag-Au bimetallic SERS hot spots  

作　　者：Xuan-Hung Pham Eunil Hahm Tae Han Kim Hyung-Mo Kim Sang Hun Lee Sang Chul Lee Homan Kang Ho-Young Lee Dae Hong Jeong Hak Soo Choi Bong-Hyun Jun 

机构地区：[1]Department of Bioscience and Biotechnology,Konkuk University,Seoul,143-701,Republic of Korea [2]Department of Nuclear Medicine,Seoul National University Bundang Hospital,Seongnam,13620,Republic of Korea [3]Gordon Center for Medical Imaging,Department of Radiology,Massachusetts General Hospital and Harvard Medical School,Boston,MA,02114,USA [4]Department of Chemistry Education,Seoul National University,Seoul,151-742,Republic of Korea

出　　处：《Nano Research》2020年第12期3338-3346,共9页纳米研究（英文版）

基　　金：This research was supported by the KU Research Professor Program of Konkuk University&funded by the Korean Health Technology R&D Project,Ministry of Health&Welfare(No.HI17C1264);Ministry of Science and ICT(No.NRF-2019R1G1A1006488).

摘　　要：Surface-enhanced Raman scattering(SERS)enables rapid detection of single molecules with high specificity.However,quantitative and sensitive SERS analysis has been a challenge due to the lack of reliable SERS-active materials.In this study,we developed a quantitative SERS-based immunoassay using enzyme-guided Ag growth on Raman labeling compound(RLC)-immobilized gold nanoparticle(Au NP)-assembled silica NPs(SiO2@Au-RLC@Ag).The enzyme amplified Ag+reduction as well as Ag growth on the RLC-immobilized Au NP-assembled silica NPs(SiO2@Au-RLC),which resulted in a significant increase in SERS signal.In the presence of target antigens such as immunoglobulinG(IgG)or prostate-specific antigen(PSA),Ab1-Antigen-Ab2 immune complex with alkaline phosphatase triggered an enzyme-catalyzed reaction to convert 2-phospho-L-ascorbic acid(2-phospho-L-AA)to ascorbic acid(AA).As produced AA reduced Ag+to Ag,forming an Ag hot spot on the surface of SiO2@Au-RLC,which enhanced the SERS signal of SiO2@Au-RLC@Ag in a solution with a target antigen concentration.The plasmonic immunoassay for IgG detection showed a high linearity of SERS intensity in the range of 0.6 to 9.0 ng/mL with a detection limit(LOD)of 0.09 ng/mL,while an LOD of 0.006 ng/mL was obtained for PSA.The results indicate that the sensitivity of our novel SERS-based immunoassay is higher than that of conventional enzyme-based colorimetric immunoassays.

关 键 词：surface-enhanced Raman scattering(SERS)-based immunoassay Au-Ag alloy surface-enhanced Raman scattering silica template immunoglobulin G(IgG)detection 

分 类 号：O65[理学—分析化学]