The identification and determination of chemical species have received significant attention due tSoe letnhieuirm misa ianc coroulnetse di na s eonnveir oonf mtheen tnaul,t rineunttsri,t ieosnsaeln,t iabli ofloorg ihcuaml, anto, xmicooslto goifc aaln imanadl sipnedcuiestsr iaanld [p1o-2ss]ibfliye lfdosr. plants, as well as a toxicant. This metalloid accomplishes important roles in the prevention of cancer and pprrootpeecrttiioens. aFgaoirn shtu tmhea nh ehaevayl thm, eotanll yto xniacrirtoyw e ffreacntgse. Aofls os,eliet nhiuams bceoenn creenptorartteiodn t hisa t usseelfeunli uamn dh aosutcsairdcei noofg etnhiics range can cause disease, due to deficiency or toxicity [2-5]. tQaurgaenttsu man dd oetvs e(nQtsD [s1),] . oMneosd oiffi ctahtei omn oosft tphreo mQiDsins gwnitahn osmuiatatebrliea lfsu,nacrteio vnearly g aropupplisc aobrl el igina nsdesn shinags oaf pdriofffoeruenndt effect on the photoluminescence response of the desired target [6]. This work presents a spectrofluorimetric method for the determination of selenite in aqueous solutions. The water soluble zinc sulfide quantum dot (ZnS QD) was synthesized using a simple and fast procedure based on the co-precipitation of nanoparticles in an aqueous solution in the presence of 3-mercaptopropionic acid (MPA), as the capping agent. Luminescent MPA-ZnS QDs, with a strong fluorescent emission at about 427 nm, was applied for the determination of selenite. The influence of the effective parameters including pH and temperature was investigated. Under the optimum conditions, the fluorescence intensity of QDs was linearly proportional to the selenite concentration in the range 40-720 μM with a detection limit of 13 μM. Moreover, the quenching mechanism was discussed to be a static quenching procedure.
