Highly Blue-fluorescent Carbon Quantum Dots Obtained from Medlar Seed for Hg2+ Determination in Real Water Samples


ÖZBEK N., Çekirge E., OCAK M., Ocak Ü. T.

Journal of Fluorescence, 2023 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1007/s10895-023-03463-1
  • Dergi Adı: Journal of Fluorescence
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Biotechnology Research Abstracts, Chimica, Compendex, MEDLINE
  • Anahtar Kelimeler: Carbon quantum dot, Fluorescence quenching, Hg2+ determination, Medlar seed, Metal ions
  • Karadeniz Teknik Üniversitesi Adresli: Evet

Özet

The carbon quantum dots (CQDs) have been prepared from medlar seeds with pyrolysis method in an oven at 300 °C. UV-vis absorption spectroscopy, fluorescence spectroscopy, Fourier transform infrared spectroscopy (FTIR) spectroscopy, x-ray diffraction (XRD) technique, x-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were used in the characterization of CQDs. CQDs, give a strong blue fluorescence under UV lamp (at 365 nm), have a quantum yield of 12.2%. The influence of metal ions such as K+, Mg2+, Ca2+, Be2+, Cr3+, Mn2+, Ni2+, Ag+, Hg2+, and Al3+ on the fluorescence properties of the CQDs was investigated by means of emission spectrophotometry. CQDs altering fluorescence characteristics depending on the excitation wavelength show selectivity for Hg2+ ions with outstanding fluorescence quenching among the tested metal ions. Based on these results, a new fluorimetric method has been developed for the determination of Hg2+ in real water samples. The linear range of method is 1.0 to 5.0 mgL− 1. Limit of detection and limit of quantification are 0.26 and 0.79 mgL− 1, respectively. The proposed method has been successfully used in determination of Hg2+ ions in tap, sea, and stream water samples with application of addition-recovery experiments.