Functionalized Reduced Graphene Oxide Sheets: An Efficient Resistive Sensing Platform for Arsenic

The demand to detect toxic arsenic ions in water is increasing due to uncontrolled industrial and human activities. Conventional detection methods are found to be very complex, cumbersome, and nonportable. Here, we propose a novel reduced graphene oxide (RGO)–Fe3O4–leucine-based device with high sensitivity and stability for selective detection of arsenic ions in water. The operating voltage of the device is 2 V, which ensures low power consumption. Fe3O4 and leucine impart a high degree of selectivity toward arsenic ions, and RGO ensures a high surface-to-volume ratio for adsorption. The device is tested against eight metal ions, which are common water contaminants and found to be highly sensitive toward arsenic. The sensitivity of the RGO–Fe3O4–leucine-based device toward arsenic is found to be 140 nA/ppb, which is very high compared to the other ions. The sensor device exhibits a response time of 21 s and is highly stable against adverse humid conditions. The sensor shows high resilience in the degradation of sensing performance for 40 days. Therefore, the RGO–Fe3O4–leucine-based device shows promising results to be used in future portable, low cost, and user-friendly arsenic ion detector systems.