ABSTRACT
A novel spirooxazine, MeOBnSPO, as a fluorescence probe was successfully synthesised and its molecular structure was confirmed by single crystal X-ray crystallographic and spectroscopic analyses. The sensing performance of MeOBnSPO for Cu2+ was achieved with a ‘turn-on’ fluorescent detection in acetonitrile. The results demonstrated that MeOBnSPO possessed high selectivity towards Cu2+ with a 10-fold enhancement in fluorescence intensity (λem = 544 nm) and high sensitivity at the micromolar concentration. The limit of detection was calculated to be 19.1 nM. Evidence for the ring opening reaction and 1:1 stoichiometric complexation of MeOBnSPO to Cu2+ was proven by 1H NMR titration, FT-IR, MS, and Job analyses. Moreover, a drastic change in colour from colourless to bright yellow could provide naked-eye detection for Cu2+ with rapid response. The viable test strips of MeOBnSPO were also developed for Cu2+ colorimetric detection in mixed acetonitrile – H2O (50:50 v/v).
GRAPHICAL ABSTRACT
Acknowledgments
W.S. would like to thank the Kasetsart University Research and Development Institute (KURDI) and the Center of Excellent for Innovation in Chemistry (PERCH-CIC), Ministry of Higher Education, Science, Research and Innovation. W.F. also thanks the Human Resource Development in Science Project (Science Achievement Scholarship of Thailand, SAST) for the support.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Supplementary material
Supplemental data for this article can be accessed online at https://doi.org/10.1080/10610278.2023.2221365