Merocyanine Dye‐Based Fluorescent Chemosensor for Highly Selective and Sensitive Detection of Hypochlorous Acid and Imaging in Live Cells

Abstract

A merocyanine dye-based fluorescent probe have been synthesised for selective and sensitive detection of hypochlorous acid. The merocyanine dye 1 can be synthesized by simple condensation reaction of 1, 1, 2, 3-tetramethyl-1H-benzo[e]indol-3-ium iodide with indole-3-carboxaldehyde. The reaction between hypochlorous acid and dye 1 is linear in the hypochlorous acid concentration range of 0 to 100 mM with a detection limit of 42 nM by fluorescent spectrometry method.The intramolecular charge transfer based fluorescent probe dye 1 displayed a considerable fluorescent spectrum at 425 nm enhancement and the color changes from red to colorless by naked eye detection in the addition of hypochlorous acid. Further supported by the 1 H NMR titrations reveal that the reactive oxygen species in dye 1 bind to the indole-NH-unit. The chemosensor also showed excellent performance when used in the "test strip" method.

Discovery of Specific Nonpeptide Probe for Chymotrypsin via Molecular Docking-Based Virtual Screening and the Application

“…The subjects of discovering those chemosensors vary from small reactive molecules (biothiols, ions, amino acids, etc. ) − to biomacromolecules (enzymes, protein receptors, etc. ) − in biological systems and even some probes can be retrofitted to detect physical parameters such as pH, pressure, and temperature .…”

Merocyanine‐Benzothiazole Chromophore‐Based Sensor for Selective Picric Acid Detection

“…Merocyanine (MC) dyes has been widely employed to investigate sensing properties towards various analytes, biological cell lines at near infrared region . Moreover, merocyanine derivatives are also used in the field of biotechnology and chemical industry .…”

Engineering of Reversible NIR‐II Redox‐Responsive Fluorescent Probes for Imaging of Inflammation In Vivo

“…We speculated that this might be due to the quinoxaline group with a strong electron-donating ability in NIR-II Cy3-962 being oxidized by HClO to form the Noxide, which can explain the change in the absorption spectrum. [29] Notably, unlike compounds NIR-II Cy3-962 and NIR-II Cy3-956, which had only one quinoxaline group each, dyes NIR-II Cy3-938 and NIR-II Cy3-988 had two quinoxaline groups each, their m/z increased by approximately 32 upon reaction with HClO (Figures S22-S25). This result further showed that quinoxaline was the main site that was oxidized in these novel NIR-II Cy3s.…”

“…The high‐resolution mass spectrometry (HRMS) show that the m / z of the NIR‐II Cy3‐962 increased from 708.3796 to 724.3745 after its reaction with HClO, indicating that an oxygen atom was added to the conjugated structure of the dye (Figure S22). We speculated that this might be due to the quinoxaline group with a strong electron‐donating ability in NIR‐II Cy3‐962 being oxidized by HClO to form the N‐oxide, which can explain the change in the absorption spectrum [29] . Notably, unlike compounds NIR‐II Cy3‐962 and NIR‐II Cy3‐956 , which had only one quinoxaline group each, dyes NIR‐II Cy3‐938 and NIR‐II Cy3‐988 had two quinoxaline groups each, their m / z increased by approximately 32 upon reaction with HClO (Figures S22–S25).…”