Development of a Colorimetric Paper Sensor for Hg 2+ Detection in Water Using Cyanuric Acid-Conjugated Gold Nanoparticles.

Hg is one of the most dangerous pollutants that can cause damage to organs and the immune system. The common detection methods of Hg require sophisticated instrumentation and a long time for analysis. The purpose of this study was to develop a sensor for the detection of Hg using filter paper immobilized by gold nanoparticles (AuNPs) conjugated with cyanuric acid (CA). The clear color change from pink to bluish purple is the response of the CA-AuNPs filter paper sensor to exposure to Hg. Detection can be observed visually with the naked eye and/or with imageJ software; the detection limit is 0.05 µM. The colorimetric response of the sensor was also selective towards Hg after testing with different metal ions. In addition, the response from the sensor was also consistent for lake water samples spiked with Hg. The results of this research provide a promising basic technology for the development of sensors that are affordable, fast, portable, and easy to use for the detection and monitoring of Hg levels in water.