Novel natural exudate as a stabilizing agent for fabrication of copper nanoparticles as a colourimetric sensor to detect trace pollutant

Abstract

Detection of trace pollutants in water has become one of the most interesting issues due to its direct relation to human health. This work exploits a simple, novel, cost-effective, and environmentally friendly method to fabricate optical copper nanoparticles (Cu NPs) as an efficient colourimetric sensor using tree gum as a stabilising and capping agent. The localised surface plasmon resonance (LSPR) band of almond gum Cu NPs (ACuNPs) is monitored using ultraviolet-visible (UV-vis) spectroscopy. With an average size of 33 nm, the ACuNPs, which were uniformly spherical, are assessed using high resolution-transmission electron microscopy (HR-TEM). The formation of pure metallic-phase crystalline ACuNPs is illustrated using x-ray diffractometry. The Cu nanostructure determines the thiocyanate (SCN−) ions in an aqueous medium as a colourimetric sensor. The ACuNPs demonstrated sensitive and selective colourimetric detection of SCN− ions based on the decrease in LSPR intensity, as monitored by a UV-vis spectrophotometer. The developed sensor is simple, rapid, and inexpensive compared to those based on precious noble metal nanoparticles and is sensitive to SCN− ions with a detection limit of 0.226 mg/l. This work presents the development of a highly effective and rapid sensor to detect SCN− ions without complex apparatuses.