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-m 2 kg −1 which is comparabl...

中文翻译：

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磁铁矿纳米颗粒的生物合成：一种生态友好且可扩展的方法

制备磁性纳米颗粒的方法要么有毒，释放有害气体，要么既费时又昂贵。为了避免这种情况，非常需要开发一种用户友好的绿色合成路线，该路线能够以合理的数量复制磁性纳米粒子。本文报道了一种使用无害，环保，经济的方法生产磁铁矿纳米颗粒的新方法。建立了使用番木瓜叶提取物生产高度结晶的生物相容性磁性纳米颗粒的协议。通过改变硝酸铁的摩尔浓度来控制还原剂的速率，并且发现1M浓度是临界摩尔浓度，在该临界摩尔浓度以上不会形成尖晶石铁氧体的纯相。番木瓜叶提取物中存在的生物分子化学附着在颗粒表面。发现该颗粒的最佳磁化强度为60 Am 2 kg -1，这是可比的。