A highly selective fluorescent probe for sulfide ions based on aggregation of Cu nanocluster induced emission enhancement

• Published in: Analyst (London) 2015-04, Vol.140 (8), p.2719-2725
• Main Authors: Li, Zenghe, Guo, Song, Lu, Chao
• Format: Article
• Language: English
• Subjects: AGGLOMERATION; Biological; Copper; Fluorescence; MICROSTRUCTURES; Nanostructure; Scanning electron microscopy; SULFIDES; X RAY SPECTROSCOPY; X RAYS; X-ray photoelectron spectroscopy
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/c5an00017c

In this study, S(2-) ions were found to enhance the fluorescence of cysteine-capped Cu nanoclusters (Cu NCs). High resolution transmission electron microscopy (HRTEM), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy-energy dispersive X-ray (SEM-EDX) measurements, zeta potential and X-ray photoelectron spectroscopy (XPS) measurements demonstrated that the S(2-) ion-induced aggregation of the Cu NCs contributed to the fluorescence enhancement of the dispersed Cu NCs. Based on these findings, a highly selective fluorescent probe was developed for the determination of H2S using the S(2-) ion-enhanced fluorescence of the as-prepared Cu NCs. The relative fluorescence intensity was proportional to the concentration of S(2-) in the range from 0.2 to 50 μM. The detection limit (S/N = 3) was 42 nM. The proposed method has been successfully applied to determine H2S produced from toys called "Fart Bomb" with recoveries of 97.6-101.8%. The results of the proposed method were in good agreement with those determined by a standard methylene blue method. This work is not only of importance for a better understanding of the aggregation induced emission (AIE) properties of the Cu NCs but also of great potential to find extensive biological applications for H2S.