An Accurate Sensing Technique for Estimation and Detection of Cr(III) in Water by Using Smartphone

This letter demonstrates a sensing technique for rapid detection and accurate quantification of Chromium(III) in water. The principle of the proposed technique is based on change of color of 3-Mercaptopropionic acid functionalized gold nanoparticle upon interaction with Chromium ion. With the increase in Chromium(III) concentration, color changes occur from red wine to blue. The colorimetric changes are captured by a smartphone for detection and quantification. Images are further processed by using MATLAB software and the concentration of Chromium(III) has been estimated. Chromium(III) concentration as low as 1.99 nM with sensitivity of 0.019 AU/nM has been detected successfully. Furthermore, the effects on the sensor response due to the presence of other interfering metal elements have also been studied. The novelty of the system is in its simple design, low-cost, rapid detection, portability, and easy to use.