Biosynthesis of magnetite nanoparticles: an eco-friendly and scalable approach

Kinnari Parekh, Jayalakshmi Nair and Anand Bhardwaj

Abstract

The method of preparing magnetic nanoparticles is either toxic, evolves hazardous gases or time consuming and expensive. To avoid this, it is very much needed to develop a user friendly, green synthetic route which can be able to reproduce magnetic nanoparticles in a reasonably good quantity. The present paper reports a novel method to produce magnetite nanoparticles using non-hazardous, eco-friendly, cost effective method. A protocol of producing highly crystalline bio-compatible magnetic nanoparticles using Carica papaya leaf extract is established. The rate of reducing agent is controlled by varying the molarity of ferric nitrate and it is found that 1 M concentration is a critical molarity above which the pure phase of spinel ferrite does not form. The biomolecules present in the Carica papaya leaf extract are chemically attached to the particle surface. The optimum magnetisation of the particles is found as 60 A-m² kg⁻¹ which is comparable to that obtained using chemical method. Thus, the aim of preparing magnetite nanoparticles using green synthesis route without using any expensive and toxic reducing agent is contended.