The controllable synthesis of multi-color carbon quantum dots modified by polythiophene and their application in fluorescence detection of Au and Hg.

Herein, hydrothermal method was used to prepare a series of multi-color polythiophene modified carbon quantum dots. Under UV excitation, fluorescence their maximum emission wavelengths appear at 612 nm, 570 nm, and 540 nm respectively. The prepared CD-BTH and CD-BN can have specific detection of Au and Hg through fluorescence quenching effect. The detection limits for Au are 3 nM and 5.4 nM respectively, and for Hg are 23 nM and 90 nM respectively. CD-KN detects Au specifically through fluorescence resonance, with a detection limit of 33 nM. Under the interference of other metal ions, three types of polythiophene modified quantum carbon dots exhibit excellent selectivity for the responsive ions. Meanwhile, this article also elucidates the law that as the electron withdrawing ability of the side chains of polythiophene derivatives increasing, the fluorescence emission peaks of the prepared polythiophene modified carbon dots shifts red and the fluorescence quantum yield is higher.