He Wei, Sun Xiangying, Weng Wenting, Liu Bin
College of Materials Science and Engineering, Huaqiao University, Key Laboratory of Molecular Designing and Green Conversions (Fujian University) Xiamen 361021 China
RSC Adv. 2018 Jul 23;8(46):26212-26217. doi: 10.1039/c8ra04581j. eCollection 2018 Jul 19.
In this study, fluorescence of self-assembled multilayers (SAMs) of carbon dots (CDs) was found to be enhanced by graphene. The number of polyelectrolyte layers can be tuned to control the distance between CDs and graphene in SAMs. The enhanced fluorescence efficiency was found to be dependent on graphene concentration, degree of graphene reduction, and the distance between CDs and graphene surface. When graphene concentration and polyelectrolyte bilayer number were set to 0.005 mg mL and 3 layers, respectively, fluorescence intensity of CDs could be increased up to 3.2 times. Tetracycline hydrochloride (Tc) could be detected by the established SAMs in the presence of graphene as the sensitivity was 2 orders higher than that of SAMs in the absence of graphene. Limit of detection of this sensing system was 0.9284 nM, which is 1-3 orders of magnitude lower than those of most of reported fluorescence sensors. This method could be successfully applied to detect trace Tc in milk samples.
在本研究中，发现石墨烯可增强碳点（CDs）自组装多层膜（SAMs）的荧光。可以调节聚电解质层数，以控制SAMs中CDs与石墨烯之间的距离。发现增强的荧光效率取决于石墨烯浓度、石墨烯还原程度以及CDs与石墨烯表面之间的距离。当石墨烯浓度和聚电解质双层数分别设定为0.005 mg/mL和3层时，CDs的荧光强度可提高至3.2倍。在石墨烯存在的情况下，所建立的SAMs能够检测盐酸四环素（Tc），因为其灵敏度比不存在石墨烯时的SAMs高2个数量级。该传感系统的检测限为0.9284 nM，比大多数已报道荧光传感器的检测限低1 - 3个数量级。该方法可成功应用于检测牛奶样品中的痕量Tc。
