Selective colorimetric detection of Cyanide from Agro products and blood plasma by a bio-active Cu(II) complex of azophenine derivative: A potential tool for autopsy investigation

An azophenine derivative based copper complex (CN-1•Cu2+) is rationally designed and unveiled herein for the first time in the realm of azophenine family, which can selectively detect cyanide from purely aqueous medium via metal-displacement approach (MDA). CN-1•Cu2+ exhibits ‘naked-eye’ chromogenic change from brown to yellow with corresponding hypsochromic shift in UV-Vis spectra having detection threshold of 0.23 µM (60 ppb) which is far below the permissible limit of CN- in drinking water set by WHO. The mechanistic course of interaction has been affirmed by experimental evidence with theoretical corroboration. A one-to-two decoder logic circuit has been formulated based on the selective recognition phenomenon. CN-1•Cu2+ can also monitor CN- in a series of environmental samples, wherefrom CN- could be recovered at an appreciable quality rate (~99.4–101.1%), escalating the real-field applicability of the developed material. Interestingly, the complex also exhibits efficacy towards recognition of endogenous cyanide from cyanogenic food sources like sprouting potatoes, bitter almonds. Moreover, CN-1•Cu2+ is equally responsive toward real-time monitoring of cyanide in different physiological samples, like blood plasma, serum with appreciable intracellular fluorescence imaging capability examined on HeLa and Candida albicans cell lines, which unambiguously could be a potential tool for autopsy investigation in cyanide-induced death cases. This is the first azophenine-based copper complex, which exhibited significant anti-bacterial activities on Bacillus subtilis and Escherichia coli, anti-mycotic activities on Candida albicans and also in-vitro anti-cancer activities on cervical cancer cell lines (HeLa).