A straightforward and sensitive "ON-OFF" fluorescence immunoassay based on silicon-assisted surface enhanced fluorescence.

A straightforward immunoassay based on silicon-assisted surface enhanced fluorescence (SEF) has been demonstrated using a silicon-based fluorescent immune substrate and silver-antibody nanoconjugate (SANC). The P-doped, (100) oriented silicon wafers are used for both fluorophore attachment and antigen immobilization. The silicon substrate offers a very low blank signal in the "OFF" state, due to its fluorescence quenching effect.