Label-free colorimetric assay for arsenic(III) determination based on a truncated short ssDNA and gold nanoparticles

Mikrochim Acta. 2021 Jan 11;188(2):38. doi: 10.1007/s00604-020-04697-7.

Abstract

A short ssDNA (Apt-21) rationally truncated from the parent 100 nt As(III) aptamer was used for colorimetric determination of As(III). Apt-21 serves dual functions, i.e., recognition of trace As(III) and regulation of AuNPs dispersion by surface attachment, while gold nanoparticles (AuNPs) functioned as colorimetric signal reporters. Under the optimal conditions, the ratio of the absorbance at 650 nm to 520 nm (A650/A520) of AuNPs changed proportionally with increasing concentration of As(III), which showed a linear relationship within the concentration ranges 1-30 ppb and 30-100 ppb with a detection limit of 0.18 ppb. The feasibility of this assay was demonstrated by determining As(III) in spiked water samples with mean recoveries ranging from 96.5-107.1%. Schematic representation of colorimetric detection of As(III) based on the short ssDNA (Apt-21) and gold nanoparticles (AuNPs).

Keywords: Arsenic determination; Colorimetry; Gold nanoparticles; Truncated short ssDNA.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aptamers, Nucleotide / chemistry*
  • Arsenic / analysis*
  • Arsenic / chemistry
  • Biosensing Techniques / methods
  • Colorimetry / methods*
  • DNA, Single-Stranded / chemistry*
  • Drinking Water / analysis
  • Gold / chemistry
  • Limit of Detection
  • Metal Nanoparticles / chemistry*
  • Rivers / chemistry
  • Water Pollutants, Chemical / analysis*
  • Water Pollutants, Chemical / chemistry

Substances

  • Aptamers, Nucleotide
  • DNA, Single-Stranded
  • Drinking Water
  • Water Pollutants, Chemical
  • Gold
  • Arsenic