Fluorescence Based Comparative Sensing Behavior of the Nano-Composites of SiO(2) and TiO(2) towards Toxic Hg(2+) Ions.

We have synthesized sulfonamide based nano-composites of SiO(2) and TiO(2) for selective and sensitive determination of toxic metal ion Hg(2+) in aqueous medium. Nano-composites (11) and (12) were morphologically characterized with FT-IR, solid state NMR, UV-vis, FE SEM, TEM, EDX, BET, pXRD and elemental analysis. The comparative sensing behavior, pH effect and sensor concentrations were carried out with fluorescence signaling on spectrofluorometer and nano-composites (11) and (12), both were evaluated as "turn-on" fluorescence detector for the toxic Hg(2+) ions. The LODs were calculated to be 41.2 and 18.8 nM, respectively of nano-composites (11) and (12). The detection limit of TiO(2) based nano-composites was found comparatively lower than the SiO(2) based nano-composites.