Nanomolar-level selective dual channel sensing of Cu2+and CN−from an aqueous medium by an opto-electronic chemoreceptor

A novel chromogenic and fluorogenic chemoreceptor exhibiting a proclivity towards Cu²⁺and CN⁻, with applications in bioimaging and molecular electronics, was developed.

Small molecular probe as selective tritopic sensor of Al3+, F- and TNP: Fabrication of portable prototype for onsite detection of explosive TNP

Schiff base organic compound (SOC) has been prepared as a tritopic chemosensor for selective sensing by fluorescence signalling towards ions like Al³⁺, F^- and explosive molecule like TNP. In general, fluorescence like photophysical property has been used for selective detection of analyte where Al³⁺ and F^- show turn-on fluorescence signal at different wavelengths (nm) however, quenching was found with TNP. As a consequence, the chemosensor has become a selective sensor for Al³⁺, F^- and TNP. Reversibility of fluorescence responses for Al³⁺ and F^- are observed in presence of ammonium nitrate and H⁺ respectively. Similar to the detection of TNP, the detection of explosive like NO₃^- salts is also essential from homeland security point of view. In the present work, the finding of reversible sequential fluorescence response can be promoted for fabrication of next generation AND-NOT-OR-NAND-XOR-XNOR-NOR based complex logic circuit which is applicable in photonics, security and other fields including inorganic and material science. In the case of TNP recognition, the pathway mainly depends on non-covalent interaction (quenching constant: 4.4 × 10⁵ M^-1) which is even better than the recently reported materials. Detection limit for Al³⁺, F^- and TNP is 1 μM, 3 μM and 500 nM respectively. DFT-D3 has been carried out to explore the host⋯guest interaction along with the structure-property correlation of the present host-guest system. All three guest analytes have been detected inside the living cell at a certain level and in its consequence, the successful in vitro recognition ability of the SOCs inside human cell line HeLa has been explored too. In real time stepping, an easy to operate and an economically affordable pocket prototype has also been fabricated for on spot detection of TNP like explosive.

How paramagnetic and diamagnetic LMOCs detect picric acid from surface water and the intracellular environment: a combined experimental and DFT-D3 study

Diamagnetic and paramagnetic luminescent metal organic complexes (LMOCs) have been reported for explosive and pollutant nitro aromatic (epNAC) recognition.

Colorimetric and fluorimetric response of Schiff base molecules towards fluoride anion, solution test kit fabrication, logical interpretations and DFT-D3 study

Two newly synthesized Schiff base molecules are herein reported as anion sensors.

Recognition of fluoride anions at low ppm level inside living cells and from fluorosis affected tooth and saliva samples

A simple Schiff base chemosensor 2-((2-(2,4-dinitro phenyl)hydrazono)methyl)-4-nitrophenol (L) has been developed as a colorimetric and fluorimetric ‘turn on’ sensor for fluoride (F⁻).

Recent advances on the chemistry of transition metal complexes of 2-(arylazo)pyridines and its arylamino derivatives

Recent advancement on the redox properties of a selection of transition metal complexes of the azoaromatic ligands: bidentate L(1) [2-(arylazo)pyridine] and tridentate HL(2) [2-(aminoarylphenylazo)pyridine] are described and compared. Due to the presence of a low lying azo-centered π*-orbital, these azoaromatic ligands may exist in multiple valent states. The coordination chemistry of the L(1) ligands was thoroughly studied during the 1980s. These complexes undergo facile reduction in solution at low accessible potentials. One electron reduced azo-complexes, though known for a long time to occur in solution, have only recently been isolated in a crystalline state. New synthetic protocols for the synthesis of metal-bound azo-radical complexes have been developed. Low-valent metal complexes such as metal carbonyls have been found to be excellent starting materials for this purpose. In a few selected cases, syntheses of these complexes were also achieved from very high valent metal oxides using triphenylphosphine as both a reducing and oxo-abstracting agent. Issues related to the ambiguities of the electronic structures in the azo-metal complexes have been discussed considering bond parameters, redox and spectral properties. Unusual redox events such as RIET (Redox-Induced Electron Transfer) phenomena in a few systems have been elaborated and compared with the known example. Novel examples of N=N bond cleavage reactions via four-electron reduction and subsequent C-N bond formation in metal-bound coordinated ligands have been noted.