Indolo[3,2 -b ]carbazole derivative as a fluorescent probe for fluoride ion and carbon dioxide detections

A π‐Conjugated Chromophore Dye and Its Functional Paper Strips for Visually On‐Site Sensing F− and Its Reaction Mechanism

“…At 511 nm, a different linear relationship between the absorption intensity ( A 511 ) and c F − is 20.0∼140.0 ×10 –6 mol/L, whose linear regression equations is A 511 =0.0019 c – 0.031 (10 –6 mol/L) with a correlation coefficient (R 2 ) of 0.9954 (Figure b). According to the definition of detection limit, three times of average deviation of A 388 or A 511 in 20 blank samples without F − utilized here, the average limits of detection (LOD) for F − at different absorption wavelengths are up to 7.8×10 –7 mol/L at 388 nm and 1.3 ×10 –6 mol/L at 511 nm respectively, far below the permissible limit of F − (1.5 mg/L) in drinking water by the World Health Organization (WHO) ,. Further from Figure c and Figure d, we could find that, the colors of both LABD solution in DMSO and its functionalized filter‐paper change gradually from light yellow to dark red by increasing c F − from 5.0 ×10 −6 mol/L to 1.4 ×10 −4 mol/L.…”

“…developed a novel disulfonamide‐based dual‐mode fluorescent and colorimetric sensor for fluoride detection by a two‐stage deprotonation mechanism. Although the traditional methods above could recognize F − with excellent performances to meet the permissible limit of F − (1.5 mg/L) in drinking water by the World Health Organization (WHO),, most of them require sophisticated instruments and cumbersome laboratory procedures, which couldn't be utilized conveniently for on‐site analyses.…”

Perylenemonoimide-Based Colorimetric Probe with High Contrast for Naked-Eye Detection of Fluoride Ions

“…The large π-conjugate system and the strong electron-withdrawing feature of PMI can be used to construct a strong donor−π–acceptor (D−π–A) structure; thus, the absorption band of PMI would undergo a significant red shift for high-contrast detection of F – . Meanwhile, compared with the frequently used amide/urea/pyrrole binding sites, − the introduction of the recognition group with strong affinity to F – (OH group) can further increase the selectivity of the probe. Therefore, the OH group is introduced to the peri position of PMI as the recognition unit.…”

“…So far, several colorimetric and fluorescent F – probes have been developed with the advantages of simple operation and high selectivity for quantitative detection. − Compared with F – fluorescent probes based on common detection mechanisms such as mesoporous silica or a silica particle-based reaction − and boron–fluoride complex formation, − probes based on hydrogen bonding (H-bonding) interactions − are more attractive due to their better sensitivity, shorter response time, better reversibility, and simpler operation without auxiliary equipment. However, most of the H-bonding interaction-based F – probes suffer from several disadvantages. , For example, they have poor selectivity and are easily interfered by other anions, such as AcO – , SO 3 2– , HPO 4 2– , and HSO 3 – . , They are also difficult to induce high-contrast color change. , Therefore, it is very important to improve the selectivity of H-bonding interaction-based F – fluorescent probes with significant color change, leading to the naked-eye detection of F – .…”

In Vivo Fluoride Ion Detection and Imaging in Mice Using a Designed Near-Infrared Ratiometric Fluorescent Probe Based on IR-780

“…In recent years, an assortment of methods, including ion-selective electrodes, ion chromatography, fluorine reagent colorimetry and fluorescent probes, − have been reported for F – detection. Among the current methods for F – assay, fluorescence probes are emerging methods for the test of various analytes, as they can be used in living systems with minimal perturbation to support overall spatiotemporal information as well as high sensitivity and selectivity.…”