ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Microwave assisted production and characterization of gold nanoparticles using green tea and catechin extracts obtained by supercritical extraction method

Gönül Serdar and Gülşah Gül Kılınç

Department of Central Research Laboratory, Karadeniz Technical University, Trabzon, Turkey

E-mail: gonulserdar@ktu.edu.tr

Received: 10 March 2023  Accepted: 2 May 2023

Abstract:

In this study, metallic gold nanoparticles (AuNPs) were to be prepared from green tea extract grown in the Eastern Black Sea region of Turkey and from 2% (w/v) aqueous solutions of catechin extract separated by SFE extraction by microwave extraction. 0.5, 1, 2, 3, 4 mL green tea and catechin extract were added separetely to HAuCl₄.3H₂O solution (0.5 mM) separately and subjected to microwave irradiation for 1, 3, 5, 10, 15, and 30 min, respectively. In addition, polyethylene glycol (PEG-200, 1%) was used as a capping agent. UV–Visible, TEM, XRD, FT-IR, and Zetasizer were used to characterize Au nanoparticles prepared according to green chemistry principles. The optimal conditions were determined by measuring the plasmon resonance absorption (SPR) spectra using the UV–Visible method. The presence of the polyphenolic biomolecules and their interaction with the surface of AuNPs was confirmed by the FT-IR spectra in comparison with the literature studies. According to the lattice planes (111), (200), (220), and (311) of the face-centered cubic gold nanostructures, the distinct Bragg reflection peaks occur at 2θ values of 38.09°, 44.22°, 64.54°, and 77.50°.The average crystallite size calculated from the XRD peaks of AuNPs was 13.14 nm. According to the results of zeta-Sizer analysis, the average particle size of Au nanoparticles synthesized by microwave extraction in an aqueous medium was 34.34 ± 4.568 nm, the zeta potential −17.1 ± 1.01 mV, and the polydispersity index was 0.405 ± 0.224. The AuNP solutions were stored in a refrigerator, and their UV–vis absorption spectra, hardly changed and were stable for about 1.5 to 2 months.

Keywords: AuNPs; Green tea; Catechins; Supercritical fluid extraction (SFE)

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02851-y

Chemical Papers 77 (9) 5155–5167 (2023)