Unveiling of a smartphone-mediated ratiometric chemosensor towards the nanomolar level detection of lethal CN: combined experimental and theoretical validation with the proposition of a molecular logic circuitry.

A promising naphthalene-functionalized ratiometric chemosensor ()-1-((naphthalen-5-yl) methylene)-2-(2,4-dinitrophenyl) hydrazine (DNMH) is unveiled in the present work. DNMH demonstrates brisk discernible colorimetric response from yellow to red in the presence of CN, a lethal environmental contaminant, in a near-perfect aqueous medium with a LOD of 278 nM. The "key role marker" controlling the electrochemical and non-covalent H-bonding interaction between DNMH and CN is through the commendable role of acidic -NH functionalities. Kinetic studies reveal a pseudo second order reaction rate and the formation of an unprecedented photostable adduct. The negative value of Δ as evaluated from ITC substantiates the spontaneity of the DNMH⋯CN interaction. The sensing mechanism was further reinforced with state-of-the-art theoretical investigations, namely DFT, TDDFT and Fukui indices (FIs). Moreover, the proposition of a reversible multi-component logic circuitry implementing Boolean functions in molecular electronics has also been triggered by the turn-over spectrophotometric response of the ditopic ions CN and Cd. The cytotoxicity of DNMH towards and is successfully investigated the MTT assay. Impressively, "dip stick" and "easy to prepare" test paper device and silica gel-based solid-phase CN recognition validate the on-site analytical application of DNMH. Furthermore, the involvement of a synergistic approach between '' and 'engineering' an exquisitely implemented smartphone-assisted colorimetric sensory prototype makes this work unprecedented among its congeners and introduces a new frontier in multitudinous material-based functional product development.