In this paper, we have proposed a simple method to covalently conjugate biotin to magnetic nanoparticles, which can be targeted to the tumour sites by using pretargeting approach with avidin or streptavidin. Magnetic nanoparticles of manganese ferrite were synthesized by alkaline coprecipitation of ferric chloride hexahydrate, ferrous sulphate heptahydrate and manganese sulphate monohydrate using ammonium hydroxide. The synthesized magnetic nanoparticles were then successfully surface modified by using 3-aminopropyl trimethoxysilane, and the amount of aminopropylsilane bound to the surface of magnetic nanoparticles was quantified by measuring the absorbance of a purple-coloured complex (Ruhemann’s purple) formed between amine group and ninhydrin at 576 nm. The aminated magnetic nanoparticles were then conjugated to biotin by reacting them with N-hydroxysuccinimide–biotin in dimethylsulphoxide. The successful conjugation of biotin to magnetic nanoparticles was confirmed by Fourier transform infrared spectroscopy. The size, phase and magnetic nature of the synthesized nanoparticles were analysed by using various techniques like transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy and vibrating sample magnetometry.

中文翻译：

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用于预靶向的生物素化磁性纳米颗粒：合成和表征研究。

在本文中，我们提出了一种简单的方法将生物素共价缀合到磁性纳米颗粒，该磁性纳米颗粒可以通过使用抗生物素蛋白或链霉亲和素的预靶向方法靶向肿瘤部位。通过使用氢氧化铵对六水合氯化铁，七水合硫酸亚铁和一水合硫酸锰进行碱共沉淀，合成了锰铁氧体的磁性纳米粒子。然后，使用3-氨丙基三甲氧基硅烷成功地对合成的磁性纳米粒子进行了表面改性，并通过测量在胺基和茚三酮之间形成的紫色络合物（Ruhemann紫色）的吸光度，定量了与磁性纳米粒子表面结合的氨基丙基硅烷的量。在576 nm处。然后，使胺化的磁性纳米颗粒与N-羟基琥珀酰亚胺-生物素在二甲亚砜中反应，使其与生物素结合。通过傅立叶变换红外光谱法证实了生物素与磁性纳米颗粒的成功缀合。通过使用各种技术，如透射电子显微镜，X射线衍射，能量色散X射线光谱法和振动样品磁力分析法，分析了合成纳米颗粒的大小，相和磁性。