A cyanide-selective colorimetric "naked-eye" and fluorescent chemosensor based on a diketopyrrolopyrrole–hydrazone conjugate and its use for the design of a molecular-scale logic device. Issue 99 (10th October 2016)

• Record Type: Journal Article
• Authors: Wang, Lingyun; Chen, Xianggen; Cao, Derong
• Is Part Of: RSC advances. Volume 6:Issue 99(2016)
• Page Start: 96676
• Page End: 96685
• Publication Date: 2016-10-10
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra21669b
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : A novel diketopyrrolopyrrole (DPP)–hydrazone based receptor was designed and synthesized as a selective fluorescent and colorimetric chemosensor for cyanide in aqueous media via deprotonation between the hydrazide moiety of the probe and cyanide. Abstract : A novel diketopyrrolopyrrole (DPP)–hydrazone based receptor1 was designed and synthesized as a selective fluorescent and colorimetric chemosensor for cyanide without interference from other common anions including fluoride and acetate. The spectral responses of1 to cyanide were studied: an approximately 130 nm red shift in absorption spectra (from λ max-ab = 516 nm to λ max-ab = 646 nm and the color change from pink to indigo) and "turn-off" emission response was observed. The experimental results revealed that the formation of anionic species from deprotonation of the hydrazone N–H moiety by cyanide was responsible for the spectral changes. Density function theory calculations were conducted to rationalize the optical response of the receptor1 . In the presence of cyanide, receptor1 could act as an "Off–On" fluorescent probe for trifluoroacetic acid (TFA) based on the reversible protonation process, which may be represented by a complementary "IMPLICATION/INHIBIT" logic gate at the molecular level employing CN − –TFA as the chemical inputs. The detection limit was 0.23 μM using the fluorescence spectra changes, which is far lower than the WHO guideline of 1.9 μM.