Abstract

Chitosan-coated magnetic nanoparticles were prepared using four different methodologies and their potentialities for DNA and Cu(II) recovery were studied. The first synthesis was done using a one-step approach, while the second one was a one-step method with pH compensation. The third methodology was done by coating the previously obtained uncoated magnetic nanoparticles and the last one was performed using glutaraldehyde as crosslinker agent after a one-step synthesis. X-Ray diffraction analysis demonstrated the crystallinity of the nanoparticles and a crystallite size between 14 and 16 nm was determined. Particle sizes between 13 and 16 nm were measured using scanning electron microscopy. The vibrational bands observed in the infrared spectrum confirmed the formation of a chitosan layer on the magnetic nanoparticles surface.The thermograms proved that the nanoparticles obtained with the first and the third methodologies resulted in particles with greater chitosan content. The highest copper adsorption capacity (22 mg/g) was obtained with the nanoparticles produced using glutaraldehyde as a crosslinker agent. The chitosan-coated nanoparticles present higher DNA adsorption capacity than the uncoated nanoparticles and the third methodology adsorbed the highest amount of DNA (27 μg).

摘要

使用四种不同的方法制备壳聚糖涂层磁性纳米粒子，并研究了它们对 DNA 和 Cu(II) 回收的潜力。第一个合成是使用一步法完成的，而第二个是使用 pH 补偿的一步法。第三种方法是通过涂覆先前获得的未涂覆磁性纳米粒子来完成的，最后一种方法是在一步合成后使用戊二醛作为交联剂进行的。X 射线衍射分析证明了纳米颗粒的结晶度，并确定了 14 和 16 纳米之间的微晶尺寸。使用扫描电子显微镜测量介于 13 和 16 nm 之间的粒径。在红外光谱中观察到的振动带证实了在磁性纳米粒子表面形成了壳聚糖层。热谱图证明用第一种和第三种方法获得的纳米颗粒产生具有更高壳聚糖含量的颗粒。使用戊二醛作为交联剂生产的纳米颗粒获得了最高的铜吸附容量 (22 mg/g)。壳聚糖包覆的纳米颗粒比未包覆的纳米颗粒具有更高的 DNA 吸附能力，第三种方法吸附的 DNA 量最高（27 μg）。