Preparation of Silver Nanoparticle-based sensor for the electrochemcialdetection of thiourea in leaching solutions of waste and electronic equipment

Abstract

Waste of electrical and electronic equipment is an interesting secondary resource of base and precious metals. Par- ticularly the use of thiourea-leaching in acidic medium was proposed for noble metals recovery. In this work, a novel and easy-to-use electrochemical sensor was developed, aimed to test thiourea from leaching solutions con- taining significant thiourea and copper amounts. The sensor was constructed using silver nanoparticles (AgNPs) de- posited on screen-printed electrodes. Its performance was studied in a synthetic leaching solution; changes in the overall surface charge of AgNPs resulting in changes in the charge-transfer resistance for the copper ions were eval- uated by electrochemical impedance spectroscopy.