Veratraldehyde Appended Organosilicon Probe and its Hybrid Silica Nanoparticles as a Dual Chemosensor for Colorimetric and Fluorimetric Detection of Cu2+ and Fe3+ ions

This article highlights the design and synthesis of Schiff base of veratraldehyde based organosilatranes and organosilocanes (3a-3c) and these were meticulously characterized with the aid of NMR (1H and 13C) and mass spectroscopic techniques. Moreover, the compound VBS (3a) was fabricated over silica nanoparticles by one-pot method which was enrichly authenticated by IR, XRD, EDX, TGA, and FE-SEM analysis. The colorimetric and fluorimetric detection of VBS and its hybrid silica nanoparticles (V-NPs) revealed their significant sensorial ability towards Cu2+ and Fe3+ over other relevant competitive metal ions. Interestingly, the binding of sensor VBS and V-NPs with Cu2+ and Fe3+ ions manifested an instant color change from yellow to light green and colorless, respectively in day light which is detectable by “naked-eye” and fluorescent turn-off response in UV-light. The results demonstrated that the organic-inorganic nanohybrids exhibited better sensitivity, greater affinity and lower limit of detection leading to better response time than the parent VBS towards Cu2+ and Fe3+ ions. The computational analysis using DFT approach was annotated to get an insight into the complexation mode of VBS with Cu2+ ion and Fe3+ ion. In addition to this, anti-oxidant properties were also investigated for compounds 3a-3c. Altogether, these findings paved the way for the design and synthesis of dual metal ion sensor.