Yang Guangming, Zhao Faqiong, Zeng Baizhao
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China; Department of Resources and Environment, Baoshan University, Baoshan 678000, PR China.
Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China.
Talanta. 2014 Sep;127:116-22. doi: 10.1016/j.talanta.2014.03.029. Epub 2014 Mar 24.
In the present study, a suspension solution containing anisotropic gold nanoparticle (GNP), chitosan (CHIT) and ionic liquid (IL, i.e. 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4]), is prepared by reducing HAuCl4 with sodium citrate in CHIT-IL aqueous solution. The hybrid solution is coated on a graphene (r-GO) modified glassy carbon electrode to construct an electrochemical sensor for the determination of theophylline (TP) and caffeine (CAF). The obtained hybrid film shows rough surface, and anisotropic GNPs are well dispersed on it. The factors concerning this assay strategy are carefully investigated, including the components of the hybrid film, the concentrations of r-GO, HAuCl4 and IL, and the pH of buffer solution. Under the optimized conditions, the linear response ranges are 2.50×10(-8)-2.10×10(-6) mol L(-1) and 2.50×10(-8)-2.49×10(-6) mol L(-1) for TP and CAF, respectively; the detection limits are 1.32×10(-9) mol L(-1) and 4.42×10(-9) mol L(-1), respectively. The electrochemical sensor shows good reproducibility, stability and selectivity, and it has been successfully applied to the determination of TP and CAF in real samples.
在本研究中，通过在壳聚糖 - 离子液体水溶液中用柠檬酸钠还原氯金酸，制备了一种含有各向异性金纳米颗粒（GNP）、壳聚糖（CHIT）和离子液体（IL，即1 - 丁基 - 3 - 甲基咪唑四氟硼酸盐，[BMIM][BF4]）的悬浮溶液。将该混合溶液涂覆在石墨烯（r - GO）修饰的玻碳电极上，构建用于测定茶碱（TP）和咖啡因（CAF）的电化学传感器。所获得的混合膜表面粗糙，各向异性的金纳米颗粒在其上分散良好。仔细研究了与该检测策略相关的因素，包括混合膜的成分、r - GO、氯金酸和离子液体的浓度以及缓冲溶液的pH值。在优化条件下，TP和CAF的线性响应范围分别为2.50×10(-8)-2.10×10(-6) mol L(-1)和2.50×10(-8)-2.49×10(-6) mol L(-1)；检测限分别为1.32×10(-9) mol L(-1)和4.42×10(-9) mol L(-1)。该电化学传感器具有良好的重现性、稳定性和选择性，并已成功应用于实际样品中TP和CAF的测定。
