Highly selective monitoring of trace radioactive I2 over organic iodides using NH2-DNA based electrochemiluminescence device

Abstract

The selective determination of radioactive I2 over organic iodides is beneficial for the efficient treatment of spent fuel and nuclear emergency. We herein develop an efficient strategy for trace I2 selective detection over organic iodide for the first time by using electrochemiluminescence (ECL) device. In detail, an I2 selective sensor is prepared by Au nanoparticles and dsDNA with -NH2 group, and then modified on indium tin oxide (ITO) electrode to obtain I2 detection device. -NH2 acts as ECL co-reactant as well as I2 selective response group, which can specifically combine with I2 in organic iodide atmosphere to quench the signal of ECL emitter (Ru(bpy)32+). This device gives a low limit of detection (5 ng/L) and high selectivity to I2 under high humidity, acidity, temperature as well as CH3I atmosphere. ECL imaging technology is applied to realize visualized accurate monitoring to trace I2 in atmosphere. Electrochemical measurement and theory calculation are further employed to demonstrate the selective mechanism of I2 detection over organic iodides. This work provides an efficient strategy and device for trace I2 specific monitoring, which exhibits a promising prospect in the fields of environment and nuclear energy.