3rd International Congress on Analytical and Bioanalytical Chemistry (3rd ICABC 2021), Elazığ, Turkey, 22 - 26 March 2021, pp.55
In this study, the synthesis and characterization of Au nanoparticles from green tea leaves
collected the Eastern Black Sea region (Of-TRABZON) were investigated. We isolated catechin
extract using Supercritical Fluid Extraction (SFE) equipped with a modifier pump was used. 10 g
of dried sample was shaken in 200 mL distilled water containing citric acid (0.1 M) for 90 min at
room temperature and extracted in a laboratoary microwave device (Milestone, Start S
Microwave, USA) at 4 minutes, 600 W and left cooling. The extracts obtained by applying
microwave extraction were completely dried in the lyophilizer and transferred to the SFE system.
Caffeine was separated by applying at 250 bar, 60 ° C and for 3 hours and then the catechin extract
was separated by applying 0.5 mL / min ethanol, modified CO2-SFE extraction under the same
conditions1
. The catechin mixture was dissolved in water (2% w/v) and used for AuNP
production. Different portions of extract solution was added to HAuCI4 solution (0,5 mM-1 mM)
and the mixture was exposed to a household microwave at 90 W for 1–30 min. The color of the
mixture started in pale yellow and become purple-red and most of the nanoparticle resonance
absorbance were between 500 and 600 nm range 2
. Absorption spectra were measured on a
Shimadzu UVP-1240 spectrophotometer. All experimental work was repeated three times