title: Core-shell nanostructures for ultrasensitive detection of α-thrombin.
abstract: We have synthesized a stable, sensitive and specific surface-enhanced Raman tag, and demonstrated its application in human α-thrombin detection. The tag consists of aptamer-modified core-shell nanoparticles with hydrophobic Au@Ag as core and silica as shell encapsulating Raman active molecules. By taking advantage of the Raman signal enhancement effect by metallic nanostructures, high stability and robustness of glass-coated core-shell nanostructures and the recognition capabilities of aptamers, we designed a sandwich detection for protein identification with high selectivity and sensitivity. In this way, we realized the ultrasensitive detection of α-thrombin. GDNs (glass-coated, dye-tagged nanoparticles), which were conjugated with oligonucleotides or antibodies, were extremely soluble in water, and had mechanical and chemical stability, easily controllable-size distribution and friendly biocompatibility. Specifically, the glass coating renders the particles amenable to use in many solvents without altering the Raman spectral response and makes agglomeration a nonfactor. All these merits open the door of the real applications in diagnostics or medical investigations in complex biofluids, such as human plasma and serum. Using the aptamer-modified GDNs as Raman tags, we successfully performed the detection of α-thrombin in human plasma. Furthermore, the overall method have been proved effective and selective, and may be implemented for multiplex target analysis simultaneously.
authors.affiliation: Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, China.
authors.forename: Xia
authors.initials: X
authors.lastname: Chen
authors.forename: Hongli
authors.initials: H
authors.lastname: Liu
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhou
authors.forename: Jiming
authors.initials: J
authors.lastname: Hu
mesh_terms: D052158:Aptamers, Peptide / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D052156:SELEX Aptamer Technique; D012825:Silicon / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman; D013917:Thrombin / Q000032:analysis*
chemical_list: D052158:Aptamers, Peptide; D012834:Silver; D006046:Gold; D013917:Thrombin; D012825:Silicon