Colloidal solution of silver nanoparticles for label-free colorimetric sensing of ammonia in aqueous solutions

Abstract

Silver nanoparticles were synthesized in the presence of saccharides and ammonia (NH3) in the concentration range from 10−2 to 103 ppm to develop an optical sensor for NH3 in aqueous solutions. Ammonia affects the features of the nanoparticles obtained in a concentration-dependent manner as determined by UV–vis absorption analysis and TEM observations. Structural and morphological analysis provides the basis for the production of a colorimetric label-free sensor for ammonia. Overall, surface plasmon resonance increases when ammonia concentration rises, although the functional trend is not the same over the entire investigated ammonia concentration range. Three different ranges have been identified: very low ammonia concentrations from 0.01 to 0.2 ppm, high ammonia concentrations from 20 to 350 ppm and, most importantly, the intermediate or physiological range of ammonia from 0.5 to 10 ppm.

Effect of pH on Size and Concentration of Silver Nanoparticles Synthesized using Ixora coccinea Linn. Leaf Extracts

“…leaf extracts affected the formation of nuclei for AgNPs synthesis resulting from increasing or decreasing number of AgNPs 17 . The spectral characteristics of the synthesized AgNPs are associated with its surface plasmon resonance (SPR) 18 Fig. 2.…”

A Green, Simple and Facile Way to Synthesize Silver Nanoparticles Using Soluble Starch. pH Studies and Antimicrobial Applications

“…It can be seen that with the increase of pH, the intensity of the absorbance increases, which also indicates an increase in the concentration of Ag-NPs [ 43 ]. At pH < 10, absorption bands are large and have a low height, which can be associated with an uneven particle distribution and a low concentration of Ag-NPs [ 44 ].…”

An efficient colorimetric inspection of ammonia using silver nanoparticles synthesized by 3‐(1‐(2‐(2,4‐dinitrophenyl)hydrazono)ethyl)‐1H‐indole as chemo‐sensors in water environment

“…[26] It is broadly employed in numerous industries, that is, fertilizers and cooling systems, dye production, medicine, plant and meat cooling, and explosives. [27][28][29][30] Ammonia poses serious health risks owing to its poisoning, and it is harmful to all animals. [26,31,32] The measurement of ammonia in body has medical implications, since it provide an indicator of illness or disease.…”