Curcumin is an active component of turmeric, isolated from the rhizomes of the plant (Curcuma longa), an ancient herbal remedy in Southeast Asia. Curcumin is known as a reducing and stabilization agent in the biological (green) synthesis of gold nanoparticles. It successfully replaces toxic reducing agents such as sodium borohydride, sodium citrate, and CTAB (cetyltrimethylammonium bromide). However, due to its hydrophobic nature, curcumin has a low solubility in water, especially at room temperature. To avoid the use of organic toxic solvents such as DMSO (dimethyl sulfoxide), in the present work, we optimized the synthesis of gold nanoparticles in an aqueous alkaline medium and, characterized the curcumin-conjugated gold nanoparticles. The synthesis was carried out in an alkaline solution (3-4 mg of freshly prepared curcumin in 10 mM NaOH), by using an excess of the gold precursor, HAuCl4 (tetra chloroauric acid). The kinetics of the reaction was followed spectrally, by the gradual disappearance of the characteristic band of curcumin at 428 nm and the emergence of the 530 nm, the plasmon band of gold nanoparticles. The average size of Au nanoparticles, calculated from the position of the band, was 14 nm, compared to around 20 nm for the citrate-coated gold. Hyperspectral imaging of curcumin-conjugated gold nanoparticles in several types of cells was investigated. The method can be scaled up and the curcumin-coated gold nanoparticles are safe to be used for medical purposes

Simona Badilescu is a senior scientist with a background in physical chemistry and a rich experience in teaching and research. She received her PhD from the University of Bucharest (Romania) and specialized in molecular spectroscopy, surface science, and analytical applications of infrared spectroscopy in an industrial environment. After three years of teaching in Algeria as an associate professor at the University of Blida, she joined the Spectroscopy Laboratory of the Université de Montréal in Canada, and later on, a multidisciplinary research group at the University of Moncton in New Brunswick. Since 2006, she has been part of the Optical-Bio Microsystems Lab at Concordia University in Montreal. Her research interest is focused on nanomaterials, plasmonic sensing, interaction of nanoparticles with cells, Indian traditional medicines, etc. Badilescu is the author of several books and book chapters and almost 300 articles and conference papers