title: SERS-based immunoassay of tumor marker VEGF using DNA aptamers and silica-encapsulated hollow gold nanospheres.
abstract: A novel SERS-based sandwich immunoassay using DNA aptamers, silica-encapsulated hollow gold nanospheres (SEHGNs) and a gold-patterned microarray was developed for sensitive detection of VEGF (vascular endothelial growth factor) angiogenesis protein markers. Here, a DNA aptamer conjugated to SEHGN was used as a highly reproducible SERS-encoding nanoprobe, and a hybrid microarray including hydrophilic gold wells and other hydrophobic areas was used as a SERS substrate. Target specific DNA aptamers that fold into a G-quadruplex structure were used as a target recognition unit instead of VEGF antibodies. The detection sensitivity was increased by 2 or 3 orders of magnitude over the conventional ELISA method. In particular, the dynamic concentration range was 3 or 4 orders of magnitude greater than that of conventional ELISA. The results demonstrate that this sensing strategy using DNA aptamers is a powerful platform for the design of novel immune-sensors with high performance. In particular, SERS-based detection using SEHGNs provides great promise for highly sensitive biomarker sensing with unprecedented advantages.
authors.affiliation: Department of Bionano Engineering, Hanyang University, Ansan 426-791, South Korea.
authors.forename: Juhui
authors.initials: J
authors.lastname: Ko
authors.forename: Sangyeop
authors.initials: S
authors.lastname: Lee
authors.forename: Eun Kyu
authors.initials: EK
authors.lastname: Lee
authors.forename: Soo-Ik
authors.initials: SI
authors.lastname: Chang
authors.forename: Lingxin
authors.initials: L
authors.lastname: Chen
authors.forename: Soo-Young
authors.initials: SY
authors.lastname: Yoon
authors.forename: Jaebum
authors.initials: J
authors.lastname: Choo
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D014408:Biomarkers, Tumor / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D054856:G-Quadruplexes; D006046:Gold / Q000737:chemistry*; D006801:Humans; D054118:Nanospheres / Q000737:chemistry*; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology; D012822:Silicon Dioxide / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D014408:Biomarkers, Tumor; D042461:Vascular Endothelial Growth Factor A; D006046:Gold; D012822:Silicon Dioxide