L-cysteine and 3-mercaptopropionic acid capped cadmium selenide quantum dots based metal ion probes
- Citation data:
Journal of Luminescence, ISSN: 0022-2313, Vol: 187, Page: 126-132
- Publication Year:
- Biochemistry, Genetics and Molecular Biology; Physics and Astronomy; Chemistry
Herein, a report on the synthesis of 3-mercaptopropionic acid (MPA) and L cysteine (Cyst) capped luminescent cadmium selenide (CdSe) quantum dots (QDs) was studied. The MPA-CdSe and Cyst-CdSe QDs were conducted with different physiologically important metal ions such as Cu 2+, Fe 2+, Zn 2+, Co 2+, Pb 2+, Mg 2+, Ni 2+ and Ag + ions in aqueous solution using fluorescence spectroscopic technique. It was found that the MPA-CdSe QDs, categorically sensitive to only Cu 2+ ions only. However, other metal ions such as Zn 2+, Co 2+, Pb 2+, Mg 2+, Ni 2+ and Ag +, did not exhibit measurable quenching. On the other hand, Cyst-CdSe QDs were very selective and sensitive to Zn 2+ ions only, which showed fluorescence enhancement while for other ions no such behavior was noticed. Thus, MPA-CdSe and Cyst-CdSe QDs have successfully detected Cu 2+ and Zn 2+ ions in the linearity range from 4 to 160 µM, respectively. The effect of fluorescence response of QDs towards metals ions were described by Langmuir-type binding model or Stern–Volmer-type equation.