Majumdar Gitanjali, Goswami Mausumi, Sarma Tridib Kumar, Paul Anumita, Chattopadhyay Arun
Department of Chemistry and Centre for Nanotechnology, Indian Institute of Technology Guwahati, Guwahati 781039, India.
Langmuir. 2005 Mar 1;21(5):1663-7. doi: 10.1021/la047440e.
In this letter, we report the synthesis of Au nanoparticles (NPs) and polyaniline (PANI) on the same cation-exchange resin beads and demonstrate their use in catalyzing the oxidation of glucose to gluconic acid by Au NPs and simultaneously in detecting the formation of the acid by the color change of PANI. The synthesis was carried out by exchanging the cations of the resins with HAuCl4 and anilinuium chloride and then reducing the metal ions by NaBH4 to produce Au NPs followed by polymerization of aniline using H2O2. The green emeraldine salt form of PANI thus obtained was treated with NaOH to be converted to blue emeraldine base before use. The deposition of Au NPs was confirmed by a change in color of the bead, visible spectroscopy, X-ray diffraction, and scanning electron microscopic measurements. On the other hand, the presence of PANI was confirmed by Fourier transform infrared (FTIR) and ultraviolet-visible (UV-vis) spectroscopy. The formation of gluconic acid from glucose was confirmed by FTIR spectroscopy. We could detect the presence of glucose of a minimum 1.0 mM concentration in water, using the present method. Our experimental observations demonstrate the possibility of the incorporation of multifunctional components on the surfaces of resins for carrying out a chemical reaction as well as detection of the product.
在本信函中，我们报道了在相同的阳离子交换树脂珠上合成金纳米颗粒（NPs）和聚苯胺（PANI），并展示了它们在催化金纳米颗粒将葡萄糖氧化为葡萄糖酸以及同时通过聚苯胺颜色变化检测酸的形成方面的应用。合成过程是通过用氯金酸和氯化苯胺交换树脂的阳离子，然后用硼氢化钠还原金属离子以生成金纳米颗粒，接着用过氧化氢使苯胺聚合。如此获得的聚苯胺的绿色翡翠盐形式在使用前用氢氧化钠处理转化为蓝色翡翠碱。通过珠子颜色变化、可见光谱、X射线衍射和扫描电子显微镜测量证实了金纳米颗粒的沉积。另一方面，通过傅里叶变换红外（FTIR）和紫外可见（UV-vis）光谱证实了聚苯胺的存在。通过FTIR光谱证实了由葡萄糖形成葡萄糖酸。使用本方法，我们能够检测出水中最低浓度为1.0 mM的葡萄糖的存在。我们的实验观察结果表明，在树脂表面引入多功能成分以进行化学反应以及检测产物是有可能的。
