The construction and application of a biomimetic sensor for determination of 4-methylbenzylidene camphor (4-MBC), an ultraviolet (UV) radiation protector, are described. The sensor was prepared by modifying a carbon paste electrode with iron(III) phthalocyanine chloride (FePcCl). Amperometric measurements carried out with the sensor under an applied potential of 0.0 V vs. Ag|AgCl in a mixture of tetrahydrofuran and 0.1 mol L-1 H2SO 4 solution (30:70 volume ratio) showed a linear response range from 1.8×10-4 to 9.0×10-4 mol L-1. A detailed selectivity investigation for other nine UV filters was also performed. A sensor response mechanism was proposed and the results for 4-MBC quantification in commercial sunscreens and in water from swimming pools and rivers are presented.