Biological synthesis of bimetallic nanoparticles of cobalt ferrate CoFe2O4 in an aqueous extract of Petroselinum crispum

Synthesized CoFe2O4 nanopowders in an aqueous extract from the leaves of Petroselinum crispum ("Green" synthesis) in an acidic and alkaline medium. Physical and chemical certification of the synthesized nanomaterials by UV spectrophotometry and scanning electron microscopy (SEM) was carried out. According to the UV spectra of CoFe2O4, obtained in an acidic medium, had a small shoulder at 242 nm and a peak at 292 nm, while the particles of alkaline nature had a plateau starting from 229 nm and a peak at 366 nm. SEM found that the synthesis environment also affects the morphology and size of CoFe2O4 bimetallic powders: during the synthesis in an alkaline medium, the particles were hemispherical in size from 30 to 100 nm, and in a slightly acidic medium (pH = 2), larger particles with cut diamond. The biological activity of cobalt ferrate was shown on the tolerance dynamics of Triticum vulgare L. plants (wheat). Wheat plants were grown in a hydroponic medium with the addition of CoFe2O4 nanoparticles in the range from 10–5 to 10–1 M to 14 days. CoFe2O4 powders of an acidic nature at concentrations of 10–2, 10–3, and 10–5 M reliably increased seed germination relative to intact samples by 48, 37, and 11%, respectively. In turn, CoFe2O4, synthesized in an alkaline medium, increased the index at dilutions of 10-3 and 10-4 M to 4 and 28%. A detailed analysis of metric indicators of T. vulgare seedlings after 14 days of exposure to CoFe2O4 allowed us to establish a higher resistance of test plants to nanopowders synthesized in an acidic medium. So, when exposed to particles synthesized in an acidic medium, in concentrations from 10-1 M to 10-5 M, an increase in the plant tolerance index of plants from 4 to 14% of the control was recorded. Alkaline CoFe2O4, under the same conditions, increased the rate from 1.2 to 16%. The intensity of the effect on the pigment apparatus of T. vulgare plants also depended on the synthesis conditions for CoFe2O4: at pH = 2, the amount of chlorophyll a decreased by no more than 2 times relative to the control, at pH = 9 - from 2 to 5 times (P≤0, 05). (paper)