Higher temperatures speed up the growth and control the size and optoelectrical properties of silver nanoparticles greenly synthesized by cashew nutshells

There is an increasing worldwide interest in utilizing cashew products and byproducts as raw materials for green synthesis of nanostructures. However, previous reports regarding the use of cashew to develop nanostructures were based on a limited amount of cashew products or byproducts, and only using the Anacardium occidentale L. The aim of the present study was to synthesize and characterize some optical, structural, electrical, molecular, and biological properties of silver nanoparticles (AgNPs) produced using a previously neglected cashew species and cashew part, the nutshells of Anacardium othonianum. Silver nanoparticles synthesis was confirmed by absorbance at a maximum of 415 nm. It was shown that the size and electrical conductivity of the AgNPs synthesized can be controlled (negatively and positively, respectively) by increasing the reaction temperature. Further, AgNPs biosynthesized by cashew nutshells were moderately cytotoxic toward yeast cells at micromolar concentration. In conclusion, a facile, eco-friendly, and cost-effective one-step method has been thermally optimized to produce size-controlled spherical-shaped and negatively-charged AgNPs with optoelectrical and antifungal properties using a cocktail of biochemical constituents from cashew nutshells as a combined reducing and coating agent. (C) 2014 Elsevier B.V. All rights reserved.