A ratiometric fluorescence and colorimetric dual-mode sensing platform based on sulfur quantum dots and carbon quantum dots for selective detection of Cu2

• Published in: Analytical and bioanalytical chemistry Vol. 414; no. 7; pp. 2471 - 2480
• Main Authors: Zhang, Hanqiang, Li, Yufei, Lu, Haixin, Gan, Feng
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2022; Springer Nature B.V
• Subjects: absorbance; Analytical Chemistry; Biochemistry; Carbon; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; color; Colorimetry; Copper; detection limit; Emission spectra; Emissions; Fluorescence; Food Science; Laboratory Medicine; Monitoring/Environmental Analysis; o-Phenylenediamine; Phenylenediamine; Quantum dots; Research Paper; Sulfur; Ultraviolet radiation; Ratiometric fluorescence; Sulfur quantum dots; Carbon quantum dots; Copper ions; Detection; Colorimetric
• ISSN: 1618-2642; 1618-2650; 1618-2650
• DOI: 10.1007/s00216-022-03888-w

A new dual-mode ratiometric fluorescence and colorimetric probe for selective determination of Cu 2+ was developed based on blue-emission sulfur quantum dots (SQDs) and yellow-emission carbon quantum dots (CQDs). The fluorescence and absorbance of CQDs increased in the presence of Cu 2+ due to the Cu 2+ -oxidized o-phenylenediamine group on the surface of the CQDs. Because of the inner filter effect between SQDs and CQDs-Cu 2+ , the fluorescence response of SQDs decreased following the introduction of Cu 2+ . Furthermore, in the presence of Cu 2+ , the dual-mode SQD–CQD probe showed visible color changes under both ultraviolet light and sunlight. Under optimal conditions, the dual-mode probe was used to quantitatively detect Cu 2+ with a linear range of 0.1–5.0 μM for ratiometric fluorescence and colorimetry, with a limit of detection of about 31 nM and 47 nM, respectively. Finally, the dual-mode probe was used for the determination of Cu 2+ in practical samples to expand the practical application, and the difference between ratiometric fluorescence and colorimetric methods was compared. The recovery results confirmed the high accuracy of the dual-mode probe, showing that it has immense potential for sensitive and selective detection of Cu 2+ in practical samples. Graphical abstract