Curcumin mediated PEG thiol acid conjugated gold nanoparticles for the determination of melamine

Abstract

Here we describe the successful preparation of gold nanoparticles (AuNPs) coated with three different poly(ethylene glycol) (mPEG thiol, PEG Thiol acid and mPEG Amine) by reducing Au3+ to Au0 using curcumin. Effect of the stabilizing agents (surfactant), pH and temperature has been studied to understand the size and shape of nanoparticles and their influence on surface plasmon resonance (SPR), fluorescence and resonance Rayleigh scattering (RRS) signals. The mPEG thiol coated AuNPs have been employed as an optical method for the determination of melamine. The combination of melamine with the AuNP decreases both SPR signal and the fluorescence intensity of the AuNPs in the range between 0 and 10 mM. The method is simple, cheap and fast with 33 nM detection limit. © 2019 Elsevier B.V.