Gold nanoparticles for the quantification of very low levels of poly-diallyldimethylammonium chloride in river water

A Simple Model to Estimate the Number of Metal Engineered Nanoparticles in Samples Using Inductively Coupled Plasma Optical Emission Spectrometry

“…The general approach involves the reduction of the chloroauric anion (AuCl 4 − ) as the gold salt and silver nitrate by various reducing agents: tri-sodium citrate, ascorbic acid, and sodium borohydride. AuCl 4 − during reduction by the reducing agents produces neutral metal atoms, which undergo nucleation and growth processes to form AuNPs in the presence of the capping molecule, tri-sodium citrate [28][29][30][31]. The characterisation of AuNPs was performed to confirm the sizes, shapes, and surface properties of nanoparticles.…”

“…The band was shifted to the longer wavelength, which confirmed the formation of nanoparticles; the band at the longer wavelength is the characteristic peak of nanoparticles. For gold metal, there was a new band at a longer wavelength between 460 and 560 nm, which is a plasmonic peak, a characteristic of AuNPs, as shown in Figure 1b [31,32] The maximum wavelength absorption (lambda maximum (λmax)) of the different sizes of metal nanoparticles obtained using different reducing agents were measured. The lambda maximum (λmax) of the plasmonic peak varied with the reduction, as shown in Table 1.…”

“…The synthesized TSC-AuNPs have spherical and irregular shapes, with an average size of 27 nm (Figure 4). AuNPs synthesized with the reducing agent tri-sodium citrate (TSC-AuNPs) resulted in nanoparticles with a particle size dimension of above 20 nm [31,32]. The TSC-AuNPs were analyzed using HRTEM, and the results are presented in Figure 4b,c.…”

Development of gold plasmonic nanoparticles for detection of polydiallyldimethylammonium chloride at Umgeni water treatment plants: An optimised study and case application

“…But the colorimetric probe-based gold nanoparticles method has an advantage over other analytical methods because it does not require many steps, it is efficient, and the colour change can be seen by the naked eye. Methods such as colloidal titration, metachromatic titration, viscometry and capillary electrophoresis have been investigated however they could not detect low concentrations (μg L −1 ) [ 24 ]. Some of those methods which were able to detect low concentrations could not achieve great accuracy and precision and also required pre-treatment and lacked efficiency [ [23] , [24] , [25] , [26] ].…”

In Situ Assembly of Gold Nanoparticles in the Presence of Poly-DADMAC Resulting in Hierarchical and Highly Fractal Nanostructures

“…Such negatively charged gold nanoparticles are obtained, normally, from wet chemical synthesis by the reduction of tetrachloroauric acid with an excess of citric or ascorbic acid, for example. The measurement of low concentrations of poly(diallyldimethylammonium) polycations in river water is another example for this analytical application [12,13]. Besides this analytical aspect, the interaction of forming metal nanoparticles with ionic surfactants and macromolecules is of interest for modulating the formation of nanoparticles and achieving different nanoparticle shapes.…”