SERS-based immunoassay of tumor marker VEGF using DNA aptamers and silica-encapsulated hollow gold nanospheres

Phys Chem Chem Phys. 2013 Apr 21;15(15):5379-85. doi: 10.1039/c2cp43155f.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aptamers, Nucleotide / chemistry*
  • Biomarkers, Tumor / analysis
  • Enzyme-Linked Immunosorbent Assay*
  • G-Quadruplexes
  • Gold / chemistry*
  • Humans
  • Nanospheres / chemistry*
  • Neoplasms / metabolism
  • Neoplasms / pathology
  • Silicon Dioxide / chemistry*
  • Spectrum Analysis, Raman
  • Vascular Endothelial Growth Factor A / analysis*

Substances

  • Aptamers, Nucleotide
  • Biomarkers, Tumor
  • Vascular Endothelial Growth Factor A
  • Gold
  • Silicon Dioxide