National Institute Of Technology Rourkela

To become an internationally acclaimed institution of higher learning that will serve as a source of knowledge and expertise for the society couple of triazole-tethered simple colorimetric, electrochemical and fluorescent chemosensors, based on ferrocene-naphthalene conjugates, C24H21ON3Fe (1) and C38H32O2N6Fe (2), have been designed and synthesized.

The interactions of 1 and 2 with several metal ions have been investigated systematically which show their strong binding affinity towards Hg2+ ion selectively.

The binding incident of both the receptors can be established either from a striking shift in redox potential (1: ΔE1/2 = 76 mV and 2: ΔE1/2 = 43 mV for Hg2+) or from a highly visual output response (colorimetric) for Hg2+ cation.

The limit of detection with Hg2+ cation was found as low as 2.6 parts per billion (ppb) and 4.5 ppb for 1 and 2 respectively, which is well below of the maximum level of Hg2+ cation in drinking water defined by EPA guidelines.

Furthermore, the sensors exhibit good sensitivity and selectivity for Hg2+ cation on paper-made test kits and on supported solid silica in aqueous environment.

The probable binding modes of these receptors with Hg2+ have also been suggested on the basis of the 1H NMR titration, ESI-MS and computational (DFT) studies along with electrochemical and spectro-photochemical data. More in Sensors & Actuators B: Chemical, 240 (2017) 640–650. (List of Research)