A highly selective colorimetric and fluorescent sensor for Hg2+, TPS (TPS = 2-(4-(diphenyl-amino)phenyl)quinazoline-4(3H)-thione), based on a 2-substituted quinazoline-4(3H)-thione derivative, was designed and characterized in this paper. TPS displays relatively strong fluorescence centered at about 468 nm. When mixing with Hg2+, TPS interacts with Hg2+ in a 2 : 1(TPS-Hg2+) stoichiometry via a coordination bond interaction between the sulfur atom and Hg2+ with an association constant of 4.17 × 108 M−2 (R2 = 0.96). Upon addition of Hg2+, TPS showed a remarkable decrease in fluorescence spectra (468 nm) with a clear color change from yellow to red, so TPS could serve as a naked-eye sensor for Hg2+. The sensor allow determination of Hg2+ in the working range 2.0 μM–12.0 μM with a detection limit of 1.5 μM. Upon addition of KI to the solution of TPS-Hg2+ species, the spectra can be restored to the original spectrum in both absorption and fluorescence and indicates that this sensor could be reused. The sensor exhibited excellent reproducibility, reversibility and selectivity.
                                    本文设计并表征了一种基于 2-取代
喹唑啉-4(3H)-
硫酮衍
生物的 Hg2+ 高选择性比色和荧光传感器 TPS(TPS = 2-(4-(二苯基
氨基)苯基)
喹唑啉-4(3H)-
硫酮)。TPS 在约 468 纳米波长处发出较强的荧光。当与 Hg2+ 混合时,TPS 与 Hg2+ 以 2 :1 (TPS-Hg2+) 的
化学计量,通过
硫原子和 Hg2+ 之间的配位键相互作用,结合常数为 4.17 × 108 M-2 (R2 = 0.96)。加入 Hg2+ 后,TPS 的荧光光谱(468 纳米)显著下降,颜色明显由黄色变为红色,因此 TPS 可作为 Hg2+ 的裸眼传感器。该传感器可在 2.0 μM-12.0 μM 的工作范围内测定 Hg2+,检测限为 1.5 μM。在 TPS-Hg2+ 溶液中加入 KI 后,吸收光谱和荧光光谱都能恢复到原始光谱,这表明该传感器可以重复使用。该传感器具有出色的再现性、可逆性和选择性。