environmentally-friendly green approach for the production of zinc nanocomplex from the extract of citrus aurantifolia waste: to evaluate its effect on the antioxidant activity of thymus daenensis

In the recent years, green synthesis of metal nanostructure (ns) is an interesting issue of the nanoscience and nanobiotechnology. there is a growing attention to biosynthesis the metal ns using organisms. among these organisms, plants seem to be the best candidate for biosynthesis of ns. ns produced by plants are more stable than that in the case of other organisms. the present investigation was carried out to green synthesis of zinc nanocomplex (zn nc) by using the waste of citrus aurantifolia, via ultrasonic probe (oscillation of 90% for 30 min). the effectiveness of this new introduced zn-fertilizer was evaluated on the antioxidant capacity of t. daenensis as the valuable and medicinal plant. the formation of nc was confirmed and characterized by uv/vis spectroscopy, x-ray diffraction (xrd), scanning electron microscopy (sem), dynamic light scattering (dls), fourier transform infrared spectroscopy (ftir), transmission electron microscopy (tem) and energy dispersive x-ray analysis (edx). the tem image indicated that the zn nc size was 18-30 nm. the zeta potential to test their stability resulted in a value of -48.8 mv. the spectrum of the xrd confirmed the hexagonal structure for zn nc in which was similar to the previously reported pattern [1,2]. the edx analysis showed the presence of carbon, oxygen and nitrogen in the zn nc. the ftir of the resultant material showed a characteristic zn-o stretching at 525 cm-1, which confirms the formation of zn nc. the sem image of zn nc showed the morphology of zn ns was hexagonal and quasi spherical. the antioxidant activity varied from 307.0 ± 2.3 µg/ml to 464.4 ± 1.4 µg/ml. application of zn nc increased the antioxidant activity of the t. daenensis extract in comparison to the control plant. increasing the content of polyphenolics by the zn nc could be a useful method to enhance antioxidant capacity and pharmaceutical properties of t. daenensis. this green synthesis approach showed that the waste of c. aurantifolia could be used as an effective stabilizing as well as reducing agent for the synthesis of zn nc.