Preparation of Silver Nanoparticles-Based Sensors for the Electrochemical Detection of Thiourea in Leaching Solutions of Waste Electrical and Electronic Equipment

Tashdjian, Agustin, Sanchez Loredo, Maria Guadalupe, Gonzalez, Graciela Alicia
Electroanalysis 2013, 25, No. 9, 2124 - 2129, 2013.


Waste of electrical and electronic equipment is an interesting secondary resource of base and precious metals. Particularly 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 containing significant thiourea and copper amounts. The sensor was constructed using silver nanoparticles (AgNPs) deposited 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 evaluated by electrochemical impedance spectroscopy.