Near-infrared fluorescent probe for tracing diquat in aqueous solutions and bioimaging in vivo

• Published in: Dyes and pigments Vol. 191; p. 109375
• Main Authors: Jiang, Xiaoxue, Rong, Lan, Cao, Jing, Fu, Nanyan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2021
• Subjects: Aggregation-disaggregation; Dicyanovinyl-modified squaraine; Diquat; Electrostatic interaction; Near-infrared fluorescent probe; Zebrafish imaging; Diquat; Aggregation-disaggregation; Near-infrared fluorescent probe; Zebrafish imaging; Electrostatic interaction; Dicyanovinyl-modified squaraine
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2021.109375

In this work, we rationally design a new type of squaraine dye SQ, modified with the dicyanovinyl motif that can specifically detect DQ (Diquat) by virtue of aggregation-disaggregation mechanism and electrostatic interaction between DQ and SQ. It undergoes H-aggregation in aqueous solution, resulting in fluorescence quenching. After the addition of DQ, the dicyanovinyl group on the probe reacts with DQ to deagglomerate so that the fluorescence is enhanced, tracing DQ in the environment with high sensitivity (LOD = 4.9 × 10−7 M), selectivity and good stability. In addition, the actual sample spike recovery experiment and the confocal fluorescence imaging experiment of DQ in zebrafish also confirmed the detection method. At present, the “turn-on” type fluorescence probe for detecting DQ by using near-infrared squaraine dye has not been reported. The application of SQ provides a new strategy for the quantification of DQ. [Display omitted] •A dicyanovinyl-modified near-infrared fluorescent probe of DQ has been synthesized.•The response was based on disaggregation of SQ initiated by interaction with DQ.•The probe exhibited high sensitivity for DQ with a detection limit of 0.49 μM.•The probe showed outstanding specificity of DQ over PQ and other herbicides.•The probe was successfully applied for visualizing DQ in zebrafish.