Gold nanoparticles functionalized with Pluronic are viable optical probes for the determination of uric acid

Abstract

The authors describe the preparation of gold nanoparticles (AuNPs) coated with poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (Pluronic F-108) by reducing Au to Au using curcumin, a natural and non-toxic food spice, in water of pH ~7 in the presence of F-108 and Ag ion. The coated AuNPs display strong resonance Rayleigh scattering (RRS) and fluorescence that results from the functionalization of the gold surface with curcumin and Pluronic F-108. The molar mass of Pluronic F-108 affects the particle size of the AuNPs formed, and small AuNPs are formed when using low molar weight F-108 that was purified by centrifugation or dialysis. The coated AuNPs were employed in an optical method for the determination of uric acid. The combination of uric acid with the AuNPs boosts both the RRS signal and the fluorescence of the AuNPs. However, higher concentrations of uric acid shift the fluorescence peak to shorter wavelengths. The method is simple, and fluorescence, best measured at excitation/emission wavelengths of 425/534 nm, increases linearly in the 50 μM to 50 mM uric acid concentration range, with a 0.14 μM detection limit which is lower than reported for other methods in the literature. Graphical abstract Pluronic F-108 capped gold nanoparticles prepared by reducing Au to Au using curcumin can estimate uric acid in 50 μM to 50 mM concentration range.

Curcumin as a novel reducing and stabilizing agent for the green synthesis of metallic nanoparticles

“…Later on, El Kurdi et al (54,64) have established new gold nanoparticles using curcumin and poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) as stabilizing agent (F-108) in neutral media. El Kurdi et al in their work have summarized the preparation of gold nanoparticles in six steps (see Figure 5):…”

Atom transfer radical polymer-modified paper for improvement in protein fixation in paper-based ELISA

“…Escherichia coli serotype O157:H7 ( E. coli O157:H7) is an epidemic human pathogen responsible for countless deaths [1, 2]. Even now, this situation still exists in undeveloped areas.…”

Outstanding Enhancement of Curcumin Fluorescence in PDDA and Silica Nanoparticles Coated DMPC Liposomes Based Nanocapsules: Application for Selective Estimation of ATP**

“…have shown ATP sensing using surface energy transfer and fluorescence recovery by rhodamine B and cucurbit [7] urilcapped gold nanoparticles assay. [32] The application of nanoparticles as detectors for biomolecules using fluorophore has enhanced the specificity and selectivity. [11,33,34,35] Besides the therapeutic activity of curcumin as anti-oxidant, anti-inflammatory and anti-caners agent, curcumin was greatly used as a fluorescent probe in optical sensing targeting several analytes.…”