This study describes immunochemical approaches for the compound-specific detection of flufenoxuron and class-specific detection of benzoylphenylurea (BPU) insecticides. With the aim of developing a highly specific immunoassay for flufenoxuron, a hapten was synthesized by introducing a spacer arm at the 2, 6-difluoro substituent aromatic ring of a flufenoxuron derivative. An IC50 value of 2.4 ppb was obtained for flufenoxuron, with ...