Microfluidic Paper-based Device for Colorimetric Detection of Mercury Ions Using Gold Nanozyme

• 1、Food School,Jiangnan University,Wuxi 214122
• 2、Food Inspection Center of Shenzhen,Shenzhen,518045

Abstract：In this paper we developed a facile and convenient microfluidic paper-based device for colorimetric detection of mercury(Hg2+) by using gold nanozyme. The colorimetric detection of Hg2+ is established based on the peroxidase-like catalytic activity of gold nanoparticles promoted by Hg2+ , which is correlated to the colorimetric intensity from the catalytic reaction of TMB and H2O2. AuNPs and Hg2+ solution were dropped on detection zones of the paper-based device. Chromogenic enzyme substrates (mixed solution of TMB and H2O2) were dropped on distribution zones of the paper-based device. By stacking the filter paper, the volume of the Hg2+ solution increased to act to filter and concentrate regents and improve the sensitivity of the detection. The assay results were recorded by scanner and then colorimetric signal analysis was carried out using ImageJ software. The linear range of Hg2+ detection was 50-2000 nmol/L and the detection limit was 17.0 nmol/L. The minimum concentration of Hg2+ that can be recognized by the naked eye was 50 nmol/L. In addition, the paper-based device was also applied to the detection of tap water and lake water samples, and the recovery was between 80% and 120%. These results indicate that the paper-based device is reliable and suitable for practical applications.

Keywords： paper-based device mercury ion gold nanoparticles colorimetric detection