Detecting protein adsorption and binding using magnetic nanoparticle probes

Magnetic force induced microcantilever bending is used to enhance sensitivity of protein biomarker detection using magnetic nanoparticles. After modifying magnetic nanoparticles and microcantilever with antibodies, the existence of antigen in solution leads to immobilization of nanoparticles on microcantilever by forming antigen–antibody complexes. The microcantilever bends in the presence of magnetic field, and the magnitude of bending is dependent on strength of magnetic field and amount of immobilized magnetic nanoparticles. This method has been used to monitor protein adsorption, and detect protein biomarker in complex biological sample system, such as cell lysate. The magnetic induced bending offers high sensitivity, does not require an asymmetric surface modification on microcantilever, and can be used for the reliable detection of protein biomarkers in body biofluids.