Fc-DNP/PVDF nanofiber matrix for selective visual detection of cyanide ion (CN−) from tobacco, food, and water samples via a ratiometric process

Abstract

A highly selective detection of cyanide ion (CN⁻) in multiple way has been achieved by Fc-DNP, an azomethine functionalized ferrocene clutched compound. The synthesized probe has been systematically characterized and the final confirmation was obtained through SC-XRD. Fc-DNP crystallises in a monoclinic crystal system with a P-1, 21/C1 centrosymmetric space group. The probe has shown excellent photophysical properties, and aggregation induced emission (AIE) property makes it an appropriate material for real-time application. The synthethised probe Fc-DNP has been incorporated with PVDF matrix via electrospinning technique to obtain Fc-DNP/PVDF nano fibre matrix. Henceforth, Fc-BPy has been deployed for the selective detection of CN⁻ in multiple methods, including naked eye colorimetric, fluorimetric and solid-state detection. The probe demonstrates a substantial color change upon introduction of CN⁻ from pale yellow to wine with significant shift in absorbance of the Fc-DNP probe from 393 nm to 501 nm distincitve indication of ratiometric detection of cyanide ion. The detection efficacy of the probe were also in solid state matrix, which exhibited commendable limit of detection (LOD) 4.90 × 10⁻¹⁰ M. The detection mechanism and stoichiometric ratio were validated through NMR titration, Jobs plot and DFT studies. Furthermore, the practical applicatbility of the probe Fc-DNP was evaluated from commercial tobacco sample, food and water samples. The recovery rate was quite astounding with the relative standard deviation (RSD) ≤1.15 %, ≤1.21 % and ≤1.33 % based on triplicate measurements. Thus, Fc-DNP emerges as a cost-effective, simple probe for CN⁻ detection across different analytical techniques.