A polysiloxane and polyvinyl alcohol interpenetrating polymer network was synthesised and its ferromagnetic derivative was used as solid support for antigen covalent immobilisation in chemiluminescent assays. Only 0.625 mug of either Trypanosoma cruzi or Schistosoma mansoni antigens immobilized onto the magnetic particles (2.5 mg) were sufficient to detect the correspondent human IgG within a nanogram scale.