A novel pyrazoline-based turn-on fluorescent probe for highly sensitive detection of Al3+ in aqueous solution and its applications

A new fluorescent sensor (E)-3-(1-acetyl-5-styryl-4,5-dihydro-1H -pyrazol-3-yl)-4-hydroxy-6-methyl-2H-pyran-2-one (DRS) for Al3+ detection was developed, and the optical properties of DRS were measured in H2O/DMSO (pH = 5.5, 99:1, V/V) solution. DRS showed notable fluorescence enhancement in the presence of Al3+ and had good selectivity and sensitivity to Al3+. Compared to the probes designed by other previous research groups, a lower detection limit (9.13 x 10(-9) M) and a shorter response time (14 s) were found. Furthermore, the Job's plot showed that the stoichiometric ratio among DRS and Al3+ was 1:1, and H-1 NMR, IR and DFT calculations showed that the sensing mechanism of the probe DRS for detecting Al3+ was chelation-enhanced fluorescence. DRS has also been applied to Al3+ ion detection in actual water samples, drugs, and HeLa cells, indicating that it has potential application value in the biological process of detecting Al3+ ion.