Switchable fluorescence of gold nanoclusters for probing the activity of alkaline phosphatase and its application in immunoassay

Biosens Bioelectron. 2016 Mar 15:77:666-72. doi: 10.1016/j.bios.2015.10.046. Epub 2015 Oct 23.

Abstract

In this work, a novel strategy for modulating the fluorescence of gold nanoclusters (Au NCs) is developed. The fluorescence of bovine serum albumin (BSA) protected Au NCs is firstly quenched by KMnO4 and then restored by ascorbic acid (AA) due to the deterioration/restoration of the surface structure. Based on which, a novel "switch-on" fluorescent assay for probing the activity of alkaline phosphatase (ALP) is developed with a detection limit as low as 0.002 U/L. In addition, this testing protocol is also expanded to the detection of the inhibitor of ALP and mouse IgG (as a model), the detection limits are 15 ng/mL for the inhibitor of 2,4-Dichlorophenoxyacetic acid (2,4-DA) and 1.5 pg/mL for mouse IgG. The present method paves a new way to develop convenient, sensitive, and selective metal NCs-based fluorescent "turn-on" probes with promising applications in versatile biosensing.

Keywords: Alkaline phosphatase; Fluorescent biosensing; Gold nanoclusters; Immunoassay.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / analysis*
  • Alkaline Phosphatase / chemistry
  • Enzyme Activation
  • Equipment Design
  • Equipment Failure Analysis
  • Gold / chemistry*
  • Immunoassay / instrumentation*
  • Metal Nanoparticles / chemistry*
  • Metal Nanoparticles / ultrastructure
  • Molecular Probe Techniques / instrumentation*
  • Molecular Probes / chemistry
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spectrometry, Fluorescence / instrumentation*

Substances

  • Molecular Probes
  • Gold
  • Alkaline Phosphatase