Recycling of Hazelnut Husk; from Bio-waste to Phyto-Assisted Synthesis of Silver Nanoparticles

Abstract

In the present work, green synthesis is utilized in the synthesis of silver nanoparticles with hazelnut (Corylus Colurna) husk which is the outer leaf part of the hazelnut shell and is considered bio-waste. According to transmission electron microscopy and x-ray diffraction analysis, the morphology of the silver nanoparticles synthesized by 0.1 g/mL hazelnut husk extract is found to be spherical with an average diameter of 6.57 nm and possesses ultra-narrow size distribution. UV-visible spectrometry reveals the absorbance peak range between 450–475 nm which is in the range of surface plasmon resonance peak of silver nanoparticles with spherical morphology. Antibacterial properties of the synthesized silver nanoparticles were tested on E. coli and significant antimicrobial activity was found with up to 79 % areal inhibition efficiency. The research revealed that the hazelnut husk extract, a reducing agent used in syntheses with different mass concentrations of hazelnut husk extract, also affects the size of the nanoparticles, allowing for the possibility of controlling their size. The antibacterial properties of silver nanoparticles, synthesized in a spherical form of different sizes, correspondingly increased their effect on bacteria which is observed in the inhibition zone. The synthesis of silver nanoparticles, which can be used in many fields for agriculture, cosmetics, and medical purposes, using plant extract and minimal chemicals is crucial because it affects its toxicity. The synthesis of silver nanoparticles with hazelnut husk not only reduces the chemical waste and toxicity, but it is both easily accessible and helps the environment and sustainability by recycling a normally considered bio-waste by-product of high-value-added crop to a technologically valuable product silver. Moreover, synthesized silver nanoparticles could be an essential part of applications ranging from antibacterial surface treatments to drug delivery systems.