Highly selective colorimetric naked-eye Cu2+ detection using new bispyrazolone silver nanoparticle-based chemosensor

In this work, we have successfully developed novel silver nanoconjugates of pyrazolone analogue and screened its chemosensing potential in aqueous medium. Bispyrazolone silver nanoparticles (Bispyra-AgNPs) were synthesised and characterised through FTIR, UV-visible spectroscopy and atomic force microscopy. The sensing ability was explored towards Ca2+, Cd2+, Co2+, Cu2+, Fe2+, Li+, Pb2+, La3+, Hg2+, Mg2+, Ni2+ and Ba2+ metal ions, respectively. Bispyra-AgNPs showed a highly quenching potential in selective recognition of Cu(2+)and colour of the solution immediately turned from yellow to purple, after the addition of Cu2+ in to the solution. The developed method also displayed a remarkable selectivity for Cu2+ over others interfering metal ions. The binding ratio and stoichiometry of host-guest complex was found to be 1:1 and determined by Job's method. The propose method is facile and sensitive to detect Cu2+ with detection limit of 10 mu M.