Recent trends and challenges in developing nanosensors for the detection of organophosphate (OP) pesticide residues in food are reviewed. Nanosensors have superior properties over the existing techniques such as high-performance liquid chromatography or gas chromatography, because they can provide rapid, sensitive, simple and low-cost on-field detection. The measurement protocols based on nanoparticles and nanotubes are also suitable for mass fabrication of miniaturized devices. The application of nanobiosensors for detection of OP agents is introduced in detail. Future prospects toward the development of selective, sensitive biosensing systems are discussed. (c) Koninklijke Brill NV, Leiden and Society of Powder Technology, Japan, 2008