THE EFFECT OF NATURAL PIGMENT OF HONEYSUCKLE ON THE OPTICAL PROPERTIES OF Au NANOPARTICLES AND Au/Ag INVERSE MICELLAR SOLUTIONS

Abstract

Non-toxic, photo-and electro-catalytic active materials, based on metal nanoparticles synthesized in reverse micelles and natural pigments, have a number of advantages for the so-called "green" approach to the production of nanocomposites with the desired properties. This paper presents the results of the study of optical properties of nanoscale silver, gold, and bimetal gold-silver nanoparticles (NPs), obtained in inverse micellar solutions (RMS) by the reaction of chemical reduction (Chem) of Meⁿ⁺ ions induced by a reducing agent belonging to a class of flavonoids, i.e quercetin and molecular oxygen. Since inverse micellar solutions are transparent systems in a wide range of spectrum, the study of optical properties (optical density spectra and luminescence spectra) of metallic and bimetal nanoparticles allowed detecting the essential difference between them. The method of UV-VIS spectrophotometry was used to measure the formation kinetics of Au, Ag NPs, and bimetal Au/Ag NPs, and their stability, depending on the storage time.

The composites based on metal nanoparticles and natural pigments are of particular interest to nanophotonics and nanoelectronics. The Lonícera caeruléa honeysuckle is one of the well-studied plants that contains valuable natural pigments. The fruit of honeysuckle is high in biologically active substances, organic acids, vitamins, tannins, and also contains coloured vegetable glycosides - anthocyanins, responsible for the blue colour of the fruit.

This paper studies the influence of the natural pigment obtained from the water-alcohol extract of honeysuckle on the optical properties of inverse micellar solutions of Au NPs. Special attention was paid to the change in characteristics of the bands of optical absorption of RMS of Au NPs with the introduction into the solution of the alcoholic extract of honeysuckle natural pigments. More data regarding optical properties of RMS of Au NPs induced by honeysuckle was obtained by studying luminescence spectra of these solutions.

As a result, metal Ag NPs, Au NPs, and bimetal Au/Ag NPs, in inverse micellar solutions, based on the chemical reduction of ions induced by a reducing agent, i.e. quercetin and oxygen, were synthesized by the method of molecular assembly.

A significant difference in the formation kinetics of monometallic Au NPs, Ag NPs, and bimetallic Au-Ag NPs was revealed.The luminescence of metal and bimetallic nanoparticles and the luminescence of honeysuckle were studied.The paper presents the results of the production of nanocomposite materials based on gold-containing nanoscale particles and natural pigments derived from the alcohol extract of honeysuckle, which can be used for research in medicine, energy production, and other sciences.