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.

Chalcone-Based Colorimetric Chemosensor for Detecting Ni2+

The first chalcone-based colorimetric chemosensor DPP (sodium (E)-2,4-dichloro-6-(3-oxo-3-(pyridine-2-yl)prop-1-en-1-yl)phenolate) was synthesized for detecting Ni2+ in near-perfect water. The synthesis of DPP was validated by using 1H, 13C NMR and ESI-MS. DPP selectively sensed Ni2+ through the color variation from yellow to purple. Detection limit of DPP for Ni2+ was calculated to be 0.36 μM (3σ/slope), which is below the standard (1.2 μM) set by the United States Environmental Protection Agency (EPA).The binding ratio of DPP to Ni2+ was determined as a 1:1 by using a Job plot and ESI-mass. The association constant of DPP and Ni2+ was calculated as 1.06 × 104 M−1 by the non-linear fitting analysis. In real samples, the sensing application of DPP for Ni2+ was successfully performed. DPP-coated paper-supported strips could also be used for detecting Ni2+. The binding mechanism of DPP to Ni2+ was proposed by ESI-MS, Job plot, UV-vis, FT-IR spectroscopy, and DFT calculations.

Synthesis of organosilocane allied N-heteroaryl Schiff base chemosensor for the detection of Cu2+ metal ions and their biological applications

N-Heteroaryl organosilocanes-based chemosensors have been synthesized for the recognition of copper metal ions with excellent selectivity.

A dual-mode highly selective and sensitive Schiff base chemosensor for fluorescent colorimetric detection of Ni2+ and colorimetric detection of Cu2

In this paper, a novel flexible Schiff base chemosensor N'-(2-hydroxy-3-methoxybenzylidene)-2-(benzamido)benzohydrazide (L) has been designed, synthesised and characterised by 1H-NMR, IR spectroscopy, ESI-MS spectrometry and single crystal XRD analysis. A significant fluorescence enhancement of L was observed only in the presence of Ni2+ ions with a detection limit of 3.64 μM whereas Cu2+ induced fluorescence quenching, although both the metals showed colorimetric responses in methanol-Tris-HCl buffer (10 mM, pH 7.2) solution (1 : 1, v/v). The single crystal structure of L-Cu2+ has also been determined. No major interference by the other effective background cations (Fe3+, Fe2+, Co2+, Zn2+, Cd2+, Hg2+, Pb2+, Cr3+, Ag+, Al3+ and Mn2+) was observed even at a higher concentration of analytes. The experimental results were further supported by DFT studies. The chemosensor L can be applied to the formation of binary logical devices, recovery of contaminated water samples and living intracellular media.

Molecular keypad controlled circuit for Ce(iii) and NO3− ions recognition by μw synthesized silicon-embedded organic luminescent sensor

This report demonstrates the mimicking of an electronic circuit diagram towards Ce(iii) ion sensing response supported by molecular keypads. The probe naphthyl based triazole linked silatrane (NTS) was efficiently synthesized using a series of microwave mediated reactions. The luminescent sensor NTS was explored for the ion sensing response towards Ce(iii) ions using DMSO and DMSO : H₂O 4 : 1 (v/v) as solvent media, respectively. The role of water in Ce(iii) ion sensing was detected as ‘turn-off’ response that contradicts the ‘turn-on’ with DMSO. Further, the sensing of NO₃⁻ ions by NTS–Ce(iii) ensemble was associated with blue shift on absorption maxima. These mimicking response studies were sketched as circuit diagrams assisted by molecular keypad behaviour as IMPLICATION output logic gate.

This report demonstrates the mimicking of an electronic circuit diagram towards Ce(iii) ion sensing response supported by molecular keypads.

Heteroaryl chalcone allied triazole conjugated organosilatranes: synthesis, spectral analysis, antimicrobial screening, photophysical and theoretical investigations

A series of heteroaryl tethered triazole conjoined organosilatranes were synthesized and studied for their solvatochromism experimentally and theoretically followed by antimicrobial screening.

Synthesis and self-assembly of luminescent hexacatenar molecules incorporating a 4,7-diphenyl-2,1,3-benzothiadiazole core

A luminescent hexacatenar molecule forms an oblique columnar liquid crystal, gels in various organic solvents, and has binding selectivity to Li⁺ in DMSO–CH₂Cl₂ solution.

Organosilatranes with thioester-anchored heterocyclic ring assembly: Cu2+ ion binding and fabrication of hybrid silica nanoparticles

Thioester allied organosilatranes were synthesized by the CDI mediated coupling of carboxylic acids with mercaptopropylsilatrane. One of the silatrane was further immobilized onto silica nanospheres, characterized and tested for copper ion binding.

A turn-on fluorescent pyrene-based chemosensor for Cu(ii) with live cell application

A pyrene-based fluorescent sensor (PHP) was synthesized for Cu(ii) detection.