Sensitive Electrochemical Detection of Thiourea Utilizing a Novel Silver Nanoparticle-Decorated Porous Silicon-Polyaniline Nanocomposite

Abstract

Thiourea (TU) causes multiple types of adverse effects on human health, and hence the monitoring of TU content in the environment and implementing proper safety procedures become vital. Therefore, in this article, we proposed an electrochemical thiourea sensor utilizing a novel silver-embedded mesoporous silicon-polyaniline (Ag@PSi-PANI) nanocomposite fabricated glassy carbon electrode (GCE) with the widest linear dynamic range (LDR = 0.02–38.7 mM) than existing TU sensors, and significantly improved other sensor parameters. Modern characterization techniques including FESEM, TEM, EDXS, XRD, XPS, and FTIR spectroscopy were employed to systematically characterize this novel Ag@PSi-PANI nanocomposite. XRD and XPS investigations confirmed the successful formation of a nanocomposite containing the PSi, PANI, and silver nanoparticles (AgNPs). TEM images revealed that AgNPs were randomly distributed onto the PSi-PANI sheets. During the electrochemical exploration via square wave voltammetry (SWV), the Ag@PSi-PANI/GCE sensor demonstrated an excellent sensitivity (1.2135 μAmM−1) and an extremely low detection limit (LOD ∼12 μM). This novel TU sensor was also employed to study the potential chemical interference utilizing some closely related chemicals, demonstrating the proper selectivity in the TU determination. During the TU determination, the Ag@PSi-PANI/GCE sensor also showed exceptional reproducibility, repeatability, and stability. The Ag@PSi-PANI/GCE sensor also showed ∼100% quantitative recovery from spiked samples. It is expected that this Ag@PSi-PANI/GCE assembly will emerge as an efficient route in developing an effective TU sensor.