Green synthesis of copper nanoparticles

VictorNowadays nanoparticle technology is very important in a lot of knowledge fields like biomedicine, electronics, catalysis, food industry… In order to prepare this nanoparticles chemical reduction in wet medium is the most used method, this method involves toxic compounds as solvent, reducing and capping agents. To avoid the use of these substances a green method based on natural cellular synthesis can be used.

This method consists in the reaction between a solution of a metal salt in water and a high antioxidant concentration plant extract, the result of this chemical reaction is the growth of metal nanoparticles. This synthesis consists in three stages: reduction, growth and stabilization. The extract has reducing and capping properties due to polyphenols and other minority compounds like enzymes, proteins, flavonoids, terpenoids, cofactors, …, which carry out the three processes.

One of the most interesting nanoparticles from biomedical point of view is copper that has cytotoxic properties, which have been demonstrated to be effectives against tumor cells or microbes, anti-inflammatory and regenerative properties. But in high concentration nanoparticles can be a problem, for this reason these nanoparticles need to be coated to dose and control the concentration, even can be functionalized with molecular receptors.

By the other hand in Castilla y Leon there is a huge production of grapes in order to obtain red wine and the wastes of this process can be used to extract antioxidant compounds. This extract is a good raw material to carry on the reaction to achieve copper nanoparticles.

Figure 1 shows the variation of particle size distribution with the time of reaction. In 3 hours the amount of particles between 0 and 200 nanometers increases and if the reaction time is increased further the particle growth continues and particles around 10 micrometers are formed.

Figure 1. Particle size distribution

Víctor Martín – Project PIP 063147181

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