Single-dip colorimetric detection of cyanide using paper-based analytic device based on immobilized silver nanoparticles

• Published in: International nano letters 2022-12, Vol.12 (4), p.399-407
• Main Authors: Budlayan, Marco Laurence, Lagare-Oracion, Jeanne Phyre, Patricio, Jonathan, De La Rosa, Lyka, Arco, Susan, Alguno, Arnold, Manigo, Jonathan, Capangpangan, Rey
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry and Materials Science; Color; Colorimetry; Contaminants; Digital imaging; Filter paper; Image analysis; Immobilization; Materials Science; Nanochemistry; Nanoparticles; Nanoscale Science and Technology; Nanotechnology; Original Article; Selectivity; Sensors; Silver; Spectrum analysis; Water purification; Water sampling
• ISSN: 2008-9295; 2228-5326
• DOI: 10.1007/s40089-022-00373-1

The need to monitor the presence of cyanide (CN − ) in water is necessary to minimize the risks to aquatic ecosystems and human health. In this paper, a paper-based analytical device (PAD) was fabricated by immobilizing silver nanoparticles (AgNPs) on filter paper (FP) for the semi-quantitative colorimetric detection of CN − in water. The average diameter of the synthesized AgNPs was estimated to be around 26.23 ± 8.37 nm, with a characteristic optical absorption peak around 420 nm. Scanning electron microscopy and energy-dispersive X-ray spectroscopy results confirmed the successful immobilization of AgNPs on the filter paper via direct immersion technique. The potential of the fabricated FP-AgNPs PAD as a colorimetric sensor for CN − was evaluated using water samples contaminated with various ions and CN − concentration. Here, a color change from yellow to colorless was instantly observed as the FP-AgNPs PAD was exposed to water samples containing CN − . Interestingly, no color change was observed for samples exposed to other analytes suggesting the good selectivity of the FP-AgNPs PAD. Ultraviolet–Visible spectroscopy results and digital image analysis revealed that the fabricated sensor can detect CN − with concentration down to 1.0 ppm. The colorimetric response was also obtained for real water samples spiked with CN − . The results stipulated in this work offer baseline information that can be used in developing highly selective and sensitive digital sensing devices for affordable, accessible, and fast water contaminant monitoring and other related applications. Graphical abstract