Department of Chemistry, East China Normal University , Shanghai 200062, People's Republic of China.
ACS Appl Mater Interfaces. 2014 Feb 26;6(4):2568-75. doi: 10.1021/am405012k. Epub 2014 Feb 7.
A novel strategy was developed for fluorescent detection of Pb(2+) in aqueous solution based on the fact that graphene oxide (GO) could quench the fluorescence of amino pyrene (AP)-grafted gold nanoparticles (AP-AuNPs) and Pb(2+) could accelerate the leaching rate of AuNPs in the presence of S2O3(2-). In this system, fluorescence reporter AP was grafted on AuNPs through the Au-N bond. In the presence of GO, the system shows fluorescence quenching because of π-π stacking between AP and GO. With the addition of Pb(2+) and S2O3(2-), the system displays fluorescence recovery, which is attributed to the fact that Pb(2+) could accelerate the leaching of the AuNPs from GO surfaces and release of AP into aqueous solution. Interestingly, the concentration of GO could control the fluorescence "turn-off" or "turn-on" for Pb(2+) detection. In addition, GO is also an excellent promoter for the acceleration of the leaching of AuNPs and shortening the analytical time to ∼15 min. Under the optimal conditions, the fluorescence Pb(2+) sensor shows a linear range from 2.0 × 10(-9) to 2.3 × 10(-7) mol/L, with a detection limit of 1.0 × 10(-10) mol/L.
开发了一种基于石墨烯氧化物（GO）可猝灭氨基芘（AP）接枝金纳米粒子（AP-AuNPs）荧光的新型策略，用于检测水溶液中的 Pb(2+)。在该体系中，荧光报告基团 AP 通过 Au-N 键接枝到 AuNPs 上。在 GO 的存在下，由于 AP 与 GO 之间的π-π 堆积，体系表现出荧光猝灭。随着 Pb(2+)和 S2O3(2-)的加入，体系显示出荧光恢复，这归因于 Pb(2+)能够加速 AuNPs 从 GO 表面的浸出，并将 AP 释放到水溶液中。有趣的是，GO 的浓度可以控制荧光的“关闭”或“开启”，从而实现对 Pb(2+)的检测。此外，GO 还是加速 AuNPs 浸出和缩短分析时间（约 15 分钟）的优异促进剂。在最佳条件下，荧光 Pb(2+)传感器的线性范围为 2.0×10(-9)至 2.3×10(-7)mol/L，检测限为 1.0×10(-10)mol/L。
