SENSOR POTENCIOMÉTRICO BASADO EN NANOPARTÍCULAS DE SULFURO DE PLATA SOPORTADAS EN MATERIALES CARBONOSOS PARA LA DETECCIÓN DE CIANURO LIBRE

Abstract

Two sensors were synthesized for the detection of free cyanide (CN-), based on silver sulfide nanoparticles (Np-Ag2S) supported on Multiwall Carbon Nanotubes (MWCNT) and hierarchical porous carbon (HPC). The Ag2S/HPC400 and Ag2S/MWCNT were characterized by physicochemical techniques such as Raman spectroscopy, X-Ray diffraction (XRD) and Scanning electron microscopy (SEM). These sensors were evaluated against the detection of free cyanide by potentiometry; the stability, reproducibility and linearity of each sensor were determined. A limit of detection of 3.34 µg L-1 and a limit of quantification of 11.05 µg L-1 for Ag2S/HPC400 sensor was obtained; while for the Ag2S/MWCNT sensor a limit of detection and limit of quantification value of 23.17 µg L-1 and 76.46 µg L-1 were obtained, respectively. The results show that the presence of carbonaceous materials with a hierarchical structure improves the limits of quantification and detection of the Ag2S/HPC400 sensor.

Keywords

• hierarchical porous carbon
• sensors
• free cyanide
• silver sulfide
• multiwall carbon nanotubes