College of Chemistry and Chemical Engineering, Graduate University of Chinese Academy of Sciences, 19A YuQuan Road, 100049 Beijing, China.
Biosens Bioelectron. 2011 Nov 15;29(1):102-8. doi: 10.1016/j.bios.2011.08.001. Epub 2011 Aug 6.
In this paper, water soluble poly(diallyldimethylammonium chloride)-graphene nanosheets (PDDA-GNs) were synthesized and characterized by UV-visible absorption spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). On the basis of PDDA-GNs, three different types of gold nanoparticles/graphene nanosheets (AuNPs/GNs) hybrid nanocomposites were obtained by one-pot synthesis, in situ reduction and adsorption methods, respectively. These nanocomposites were used as electrode materials for electrochemical determination of uric acid (UA). The results indicated adsorption to be the best method to synthesize hybrid nanocomposites from the electrochemical point of view. Given the fact positively charged PDDA-AuNPs could interact with negatively charged UA molecules, we then synthesized PDDA-protected gold nanoparticles/graphene nanosheets (PDDA-AuNPs/GNs) hybrid nanocomposites by adsorption method, for the first time. As were expected, PDDA-AuNPs/GNs gave better performance for UA than AuNPs/GNs obtained by adsorption, and the anodic peak current of UA obtained by cyclic voltammetry (CV) increased 102.1-fold in comparison to bare GCE under optimizing conditions. Differential pulse voltammetry (DPV) was used to quantitatively determine UA. The linear range of UA was from 0.5μM to 20μM and the detection limit was 0.1μM (S/N=3) with a high sensitivity of 103.08μAμM(-1)cm(-2). The assay results of urine sample provided satisfying recoveries by standard addition method. In addition, the anodic peaks of adrenaline (AD) and UA were well resolved at PDDA-AuNPs/GNs modified electrode, while they were too overlapped to separate at bare electrode, as a result of that UA was successfully detected in the presence of AD. In conclusion, rapid synthesis of PDDA-AuNPs/GNs were realized and applied as an advanced hybrid electrode material for UA determination.
本文通过紫外-可见吸收光谱、X 射线衍射（XRD）和 X 射线光电子能谱（XPS）合成并表征了水溶性聚二烯丙基二甲基氯化铵-石墨烯纳米片（PDDA-GNs）。基于 PDDA-GNs，通过一锅合成、原位还原和吸附法分别获得了三种不同类型的金纳米粒子/石墨烯纳米片（AuNPs/GNs）杂化纳米复合材料。这些纳米复合材料被用作电化学测定尿酸（UA）的电极材料。结果表明，从电化学角度来看，吸附是合成杂化纳米复合材料的最佳方法。由于带正电荷的 PDDA-AuNPs 可以与带负电荷的 UA 分子相互作用，我们随后通过吸附法首次合成了 PDDA 保护的金纳米粒子/石墨烯纳米片（PDDA-AuNPs/GNs）杂化纳米复合材料。不出所料，与吸附法获得的 AuNPs/GNs 相比，PDDA-AuNPs/GNs 对 UA 表现出更好的性能，在优化条件下，通过循环伏安法（CV）获得的 UA 的阳极峰电流与裸 GCE 相比增加了 102.1 倍。采用差分脉冲伏安法（DPV）定量测定 UA。UA 的线性范围为 0.5μM 至 20μM，检测限为 0.1μM（S/N=3），灵敏度为 103.08μAμM(-1)cm(-2)。通过标准加入法对尿样的测定结果进行了令人满意的回收率。此外，在 PDDA-AuNPs/GNs 修饰电极上，肾上腺素（AD）和 UA 的阳极峰得到很好的分离，而在裸电极上则过于重叠无法分离，因此在 AD 存在的情况下成功地检测到了 UA。总之，实现了 PDDA-AuNPs/GNs 的快速合成，并将其作为一种先进的杂化电极材料应用于 UA 的测定。
