A naked eye fluorescent chemosensor for Zn2+ based on triphenylamine derivative and its bioimaging in live cells

A Fluorescent and Colorimetric Chemosensor Detecting Pd2+ Based on Chalcone Structure with Triphenylamine

A fluorometric and colorimetric chemosensor DiPP ((E)-3-(4-(diphenylamino)phenyl)-1-(pyridin-2-yl)prop-2-en-1-one) based on chalcone structure with a triphenylamine group was synthesized. Sensor DiPP detected Pd2+ with fluorescence turn-off and via colorimetry variation of yellow to purple. The binding ratio of DiPP to Pd2+ turned out to be 1 : 1. Detection limits for Pd2+ by DiPP were analyzed to be 0.67 µM and 0.80 µM through the fluorescent and colorimetric methods. Additionally, the fluorescent and colorimetric test strips were applied for probing Pd2+ and displayed that DiPP could obviously discriminate Pd2+ from other metals. The binding feature of DiPP to Pd2+ was presented by ESI-mass, Job plot, NMR titration, ESI-mass, and DFT calculations.

A Fluorescent Probe Based on the Hydrazone Schiff Base for the Detection of Zn2+ and its Application on Test Strips

A novel fluorescent probe SHK for Zn²⁺ detection was designed based on the hydrazone Schiff base, successfully synthesized by Suzuki coupling and condensation reactions. The probe SHK in DMSO/H₂O showed extremely weak fluorescence. However, the solution exhibited an intensive yellow-green emission with the introduction of Zn²⁺. In contrast, negligible fluorescence change was observed when other metal ions were added, suggesting a high selectivity of SHK for Zn²⁺ detection. The Job's Plot analysis revealed that a 1:1 stoichiometric adduct SHK-Zn²⁺ formed during the Zn²⁺ sensing. The binding constant of the complex was determined to be 184 M^- 1, and the detection limit for Zn²⁺ was calculated to be 112 µM. Moreover, the probe SHK achieved selective fluorescence sensing for Zn²⁺ on test strips, which guaranteed its practical application prospect.

A 2-Hydroxy-1-naphthaldehyde Schiff Base for Turn-on Fluorescence Detection of Zn2+ Based on PET Mechanism

Zinc ion is closely related to human health. Its content in human body is small, while the effect is large. However, it is not the more the better, must be in a scientific balance. Therefore, it is significant to the rapid detection of Zn2+ in the environment and organism. Herein, a fluorescent probe based on 2-hydroxy-1-naphthalene formaldehyde and furan-2-carbohydrazide was conveniently synthesized via Schiff base reaction. And this probe has been successfully applied to the accurate and quantitative detection of Zn2+ in real samples, showing turn on fluorescence, good selectivity, very low detection limit, real time response and reusability. In addition, this probe has the potential application to trace Zn2+ in living cells with low cytotoxicity.

A Review on Schiff Base Fluorescent Chemosensors for Cell Imaging Applications

Fluorescent determinations of analytes have proven to be a powerful method due to their simplicity, low cost, detection limit, rapid photoluminescence response, and applicability to bioimaging. Fluorescence imaging as a powerful tool for monitoring biomolecules within the living systems. Schiff base has been extensively used as strongly absorbing and colorful chromophores in the design of chemosensors. In recent years, Schiff base based fluorescent probes have been developed for the detection of various toxic analytes and imaging of various analytes in biological systems. This review gives an overview of the important fluorescent sensors which are based on Schiff base, their approaches for molecular recognition, and their potential application in bioimaging studies.