One-pot Preparation of Creatinine-functionalized Gold Nanoparticles for Colorimetric Detection of Silver Ions

Abstract

Creatinine-functionalized AuNPs (CreAuNPs) were prepared via a facile one-pot reaction of sodium borohydride and the mixture solution of gold(III) chloride trihydrate and creatinine. The morphology and surface state of as-prepared CreAuNPs were characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. All the results demonstrated that CreAuNPs were spherical with an average diameter of about 4.2 nm, and creatinine existed on the surface of AuNPs via Au-N interaction. The as-prepared CreAuNPs exhibited a weak surface plasmon resonance (SPR) absorption owing to their small size, while the addition of Ag + could induce the aggregation of spherical CreAuNPs, producing a strong SPR absorption and apparent color change from colorless to purple owing to the surface plasmon coupling. On this basis, a colorimetric assay for Ag + was established. The assay could selectively detect Ag + as low as 1 μM with a good linearity in the range of 5-40 μM. Additionally, the assay was successfully applied to the determination of Ag + in tap water, lake water, and river water samples.

Application of synthesized copper nanoparticles using aqueous extract of Ziziphus mauritiana L. leaves as a colorimetric sensor for the detection of Ag+

“…Comparative results of the currently developed colorimetric sensor with already reported studies [12,14,[33][34][35][36] are illustrated in Table 1. Although, AuNPs were successfully applied as sensors for the detection of Ag + , the good ranges but the use of Au salts makes these sensors highly expensive.…”

Ultrasensitive colorimetric detection of creatinine via its dual binding affinity for silver nanoparticles and silver ions

“…32 Upon the addition of creatinine to the citrate-capped Ag NPs, the creatinine will replace the citrate ions to form the creatinine-capped Ag NPs. The subsequent addition of Ag(I) ions will form Ag(I)-N and Ag(I)-p coordination bonds with creatinine, 28,29 resulting in Ag NPs aggregation and colour change.…”