Functionalized surface for electrochemical sensing of electrochemically inactive alkali metal ion

The binding of Na+ ion to the ionophore 4-aminobenzo-crown-5 has been monitored by cyclic voltammetry using the redox couple Fe(CN)63-/Fe(CN)64- as a mediator redox probe. The recognition properties of the ionophore covalently bound to 11-MUA self assembled monolayer on gold surface is found to be selective for Na+ ion over Li+ and K+ ions. The self-assembled sensor interface is highly stable, reproducible and shows good sensitivity for detection of Na+ ion. The host-guest recognition of the simple crown ether derivative makes the system highly promising for real-time applications for selective detection of electrochemically inactive alkali metals by electrochemical transducer.

Label free biosensor for screening estrogenic activity

640-645Estrogens and estrogen mimics prevalent in aquatic environment are of great environmental concern because of their endocrine disrupting and carcinogenic activities. Looking to the wide variety of natural as well as structurally different synthetic estrogen mimics, a reliable in-vitro assay is required for screening the estrogenic activity of endocrine disrupting compounds (EDCs). Surface plasmon resonance (SPR) is one of the most promising analytical tools to monitor the high-performance biomolecular interactions in a label free, real time format. Present paper demonstrates a facile SPR based affinity bioassay employing estrogen receptor-α, human (hERα) functionalized self assembled monolayer covalently bound onto the gold sensor chip as recognition species. A successful interaction of potential estrogen mimics with estrogen receptor is evidenced by net rise in SPR angle. The assay has been validated in terms of optimum experimental conditions and specificity with estrogen as a positive control showing maximum estrogenic activity. As a proof of concept, proposed affinity assay is tested for screening the estrogenic activity of progesterone, pregnenolone, tamoxifen, and bisphenol-A as representative examples of potential EDCs of different classes

Functionalized surface for electrochemical sensing of electrochemically inactive alkali metal ion

934-938The binding of Na+ ion to the ionophore 4-aminobenzo-crown-5 has been monitored by cyclic voltammetry using the redox couple Fe(CN)63-/Fe(CN)64- as a mediator redox probe. The recognition properties of the ionophore covalently bound to 11-MUA self assembled monolayer on gold surface is found to be selective for Na+ ion over Li+ and K+ ions.The self-assembled sensor interface is highly stable, reproducible and shows good sensitivity for detection of Na+ ion. The host-guest recognition of the simple crown ether derivative makes the system highly promising for real-time applications for selective detection of electrochemically inactive alkali metals by electrochemical transducer

Synthesis of multidentate ligands via reduction of Schiff base-zinc(II) complex and their use for in situ synthesis of potentially biomimetic Type I copper complexes

1508-1511In an attempt to simulate the properties of blue copper proteins three low molecular weight and low symmetric solid copper(II) complexes have been synthesized. Ligands with highly asymmetric coordination environment have been prepared in two steps. The first step involves synthesis of zinc-coordinated Schiff base of benzothiazolines, which are then subjected to reduction followed by removal of the metal ion from these reduced complexes. The free ligands thus generated are then used for in situ complexation with Cu(II). These complexes exhibit an intense S→Cu(II) charge transfer band at ≈ 600 nm with high extinction values, which is characteristic of Type I copper complexes. The conductivity, magnetic susceptibility and IR studies also support the assigned structures to the complexes