Detection of Heavy Metals in Water Environment Using Nafion-Blanketed Bismuth Nanoplates

In this study, we developed Nafion-blanketed bismuth nanoplates for the ultrasensitive detection of heavy metals in water. The Nafion-blanketing method was proposed owing to its selective adsorption of cadmium and lead ions. In addition, eco-friendly bismuth nanoplates can be facilely fabricated by irradiation with ultrasonic energy. The bismuth nanoplates were used as electrochemical sensors owing to their high affinity toward heavy-metal ions. The bismuth nanoplates exhibited an outstanding electrical plasmon effect, which improved the sensitivity of the anodic stripping voltammetry sensor. We optimized the synthesis conditions for bismuth nanoplates to fabricate electrochemical sensors exhibiting excellent detection performance. In addition, the Nafion membrane was coated on the electrode to enhance the Cd 2+ and Pb 2+ detection performance through the cation-exchange characteristics and interference-protection effects of Nafion. The detection limits of the Nafion-blanketed bismuth nanoplates for Cd 2+ and Pb 2+ were 0.376 and 0.178 nM, respectively. Furthermore, the Nafion-blanketed bismuth nanoplates exhibited outstanding sensing performance in real samples such as tap water and effluent.