Nanochemistry and biotechnology

Obtaining of gold nanoparticles by using mechanochemico-biological activation
Ficeriová J.1, Dutková E.1, Harvanová J.2
1Institute of Geotechnics, Slovak Academy of Sciences, Watsonova 45, 04001 Košice, Slovakia.
E-mail: ficeri@saske.sk

2University of Veterinary Medicine and Pharmacy in Košice, Komenského 73, 04181 Košice, Slovakia.

The use of gold in various industries sectors, the shortage of primary raw materials and the demanding processing of gold-containing concentrates have given an incentive to search the application of new ways to obtain this precious metal. One of the new options is a use of the mechanochemico-biological process by which gold nanoparticles were obtained from the refractory arsenopyrite concentrate. Mechanochemical activation of this sulphide concentrate and siliceous shells of specified limnetic algae of genera (Dinobryon, Surirella) in the thiourea solution caused changes in the physico-chemical properties of gold minerals as well as algae mineral constituents. These structural changes have a decisive influence on the formation of gold nanoparticles into thiourea solution under the specific reaction conditions, from which they are subsequently fixed in the cellular matrix of mechanochemically activated algal shells. Extraction of gold nanoparticles was induced by biomolecules which secrete algal cells when they defend against the chemical effect of metal ions present in the solution [1, 2]. Gold nanoparticles were obtained after ninety minutes by described mechanochemico-biological process. In the case of thiourea leaching of arsenopyrite concentrate in the presence of algae without using of mechanochemical activation, no gold nanoparticles were obtained even after four hours. 
Gold nanoparticles can have various utilization in practice, such as accelerating the breakdown of hazardous substances or disposal of pollutants from contaminated water, soil and air. Obtaining of gold nanoparticles through this process would also lead to the elimination of algae from the aquatic environment where they are dangerous not only for aquatic plants and animals, but also for humans.

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2.	Vítová M., Čížková M., Zachleder V. Lanthanides and Algae // Int. Open-Book Lanthanides.-2019.-P. 87-111.