Optical paper-based sensor for ascorbic acid quantification using silver nanoparticles

Talanta. 2015 Aug 15:141:188-94. doi: 10.1016/j.talanta.2015.03.067. Epub 2015 Apr 9.

Abstract

In this paper, we demonstrate for the first time the use of silver nanoparticles (AgNPs) for colorimetric ascorbic acid (AA) quantification in a paper-based sensor. This device is constituted by spot tests modified with AgNPs and silver ions bordered by a hydrophobic barrier which provides quantitative and fast analysis of AA. In addition, this device is employed as point-of-care monitoring using a unique drop of the sample. AgNPs paper-based sensor changed from light yellow to gray color after the addition of AA due to nanoparticle growth and clusters formation. The color intensities were altered as a function of AA concentration which were measured by either a scanner or a homemade portable transmittance colorimeter. Under the selected measurement conditions, results presented limit of detection which was comparable to analytical laboratory-based methodologies. In addition, the sensitivity of our sensor was comparable to the standard titration method when real samples were investigated.

Keywords: Ascorbic acid detection; Colorimetric analysis; Paper-based device; Sensor; Silver nanoparticles.