A novel spectrofluorimetric method using optical sensor Eu³⁺-ACAC as a highly selective photo probe to determine Pregabalin in biological samples and pharmaceutical form

A novel spectrofluorimetric method with high selectivity and sensitivity was created to determine Pregabalin (PG) in pharmaceutical form, human serum, and urine. This method relies on detecting quenching in the intensity of luminescence of the europium acetylacetone complex (Eu³⁺-ACAC) at emission wavelength λ_em = 616 nm, which results from interaction with various concentrations of PG after excitation at λ_ex = 395 nm and pH 6.5 in dimethylformamide (DMF). The calibration curve was generated using concentrations ranging from 7.6 × 10^-8 to 6.3 × 10^-6 mol/L. The plot showed a high correlation coefficient (r²) of 0.994 with a detection limit (LOD) of 2.81 × 10^-8 mol/L and a quantification limit (LOQ) of 8.5 × 10^-8 mol/L. The remarkable luminescence intensity quenching of the Eu³⁺-ACAC by ranged concentrations of PG was effectively employed as a photo probe to determine PG in marketable form and different body fluids. Spectroscopic characterization, such as absorption and emission spectra, confirmed the obtained sensor. The improved method is verified using a range of characteristics, such as accuracy, precision, selectivity, linearity, and robustness.