Multi-level fluorescent logic gate based on polyamine coated carbon dots capable of responding to four stimuli

Abstract

The current C-dots-based logic gate has only single logic function. It still retains a tremendous challenge for constructing multiple inputs C-dots-based logic gate with reprogrammable logic functions and their combination for logic gate applications. Herein the C-dots enhanced by Zn2+ have been developed for detection of Cu2+ and S2− via inner filter effect and formation of nonemissive ground state complex, respectively. Based on the polyamine coated C-dots capable of simultaneously responding to four stimuli including Zn2+, Cu2+, S2− and H+ (pH 2.0), when definition of output intensity of fluorescence (Ioutput) > original one (Iorigin) as output = 1, and various stimuli and their combinations as inputs were adopted, the YES, INH, and integrative NOR and INH logic gates were therefore constructed. Whereas only Ioutput ≥ Iorigin was defined as output = 1, as a result of establishment of NOT, NOR, and integrative IMP plus NOR plus AND logic gates. The above logic gates are the most complicated C-dots-based ones to date, demonstrating that chemical information have been successfully transferred from one logic gate to another by chemical induction, and opening up a promising door to construct next generation of molecular devices.