T HE EFFICIENCY of the excited-state interaction between Eu 3+ doped in sol-gel matrix and the industrial product ciprofloxacin of (CFX) has been studied in different solvents and pHs. A high luminescence intensity peak at 617 nm of europium-ciprofloxacin complex at λ ex =365 nm in acetonitrile was obtained. The photophysical properties of the red emissive Eu 3+ complex doped in sol-gel matrix have been elucidated, the europium was used as optical sensor for the assessment of ciprofloxacin in the pharmaceutical tablets and serum samples at pH 8.0 and λ ex = 365 nm with a concentration range of 5.0 ×10 −9-1.0 ×10 −6 mol L −1 for ciprofloxacin, correlation coefficient of 0.987 and detection limit of 1.65 ×10 −9 mol L −1 .