β-cyclodextrin functionalised silver nanoparticles as a duel colorimetric probe for ultrasensitive detection of Hg2+ and S2- ions in environmental water samples

Herein, determination of dangerous mercury cation (Hg2+) and sulfide anion (S2-) using beta-cyclodextrin functionalised silver nanoparticles (beta-CD AgNPs) based on both naked eye visual approach and optical spectrophotometry were expressed. The beta-CD AgNPs were prepared by wet chemical method and it exhibits surface plasmon resonance (SPR) band at 400 nm. The developed sensing approach can be simply executed by introducing the premixing of Hg2+ and S2- ions into the beta-CD AgNPs colloidal solution. The colour of the beta-CD AgNPs changes from yellow to colourless while adding the both analytes, whereas, SPR band at 400 nm was decreased with blue shift for the addition of Hg2+ ions and decreased SPR band with no notable shift for the addition of S2- ions were observed. Moreover, it further appraise the practical applicability of the present nanoprobe to real sample analysis of Hg2+ and S2- ions in different water samples were also investigated.