Metal-enhanced fluorescent detection for protein microarrays based on a silver plasmonic substrate

Analyst. 2014 Apr 7;139(7):1653-60. doi: 10.1039/c3an01875j.

Abstract

This paper presents an ultrasensitive fluorescent detection method through fabricating a silver microarray substrate. Silver nanoparticles (AgNPs) and Ag@Au core-shell nanoparticles with different sizes were first synthesized by a seed-mediated growth method and the metal-enhanced fluorescence of these nanoparticles on different fluorescent dyes was investigated. The results indicated that AgNPs could act as a versatile and effective metal-enhanced fluorescence material for various fluorophores, whereas the enhanced fluorescence from Ag@Au was limited only to certain fluorophores. When the AgNPs were functionalized with aptamers and fluorescent dyes, a good analytical performance for simultaneous detection of human IgE and platelet-derived growth factor-BB (PDGF-BB) could be obtained. AgNPs were not only used as detection tags but also used to fabricate the plasmonic microarray substrate to further enhance the sensitivity of fluorescent detection. As a result, a linear response to PDGF-BB concentration was obtained in the concentration range of 16 pg mL(-1) to 50 ng mL(-1), and the detection limit was 3.2 pg mL(-1). In addition, the AgNP modified plasmonic microarrays showed remarkable recovery and no significant interference from human serum when applied to 2 ng mL(-1) PDGF-BB concentration. The plasmonic microarray substrate demonstrated both high specificity and sensitivity for protein microarray detection and this novel approach has great potential for ultrasensitive detection of protein biomarkers in the bio-medical field.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Becaplermin
  • Fluorescence
  • Fluorescent Dyes / chemistry*
  • Humans
  • Immunoglobulin E / analysis*
  • Limit of Detection
  • Metal Nanoparticles / chemistry*
  • Particle Size
  • Protein Array Analysis / instrumentation
  • Protein Array Analysis / methods*
  • Proto-Oncogene Proteins c-sis / analysis*
  • Sensitivity and Specificity
  • Silver / chemistry*
  • Surface Plasmon Resonance

Substances

  • Fluorescent Dyes
  • Proto-Oncogene Proteins c-sis
  • Becaplermin
  • Immunoglobulin E
  • Silver