Biological detection device

The invention discloses a biosensor which comprises an optical signal detection device, the device comprises an optical sensor pixel array comprising a plurality of optical sensor pixels; the biosensor further comprises an optical signal filtering layer which comprises a plurality of repeated laminated layers, a metal nanometer light condensation unit array layer which comprises a plurality of metal nanometer light condensation units and is used for focusing incident light signals; a grating array layer which comprises a plurality of micro gratings and is used for constraining the incident light signals; a biological material bearing area which comprises a plurality of sample gathering units, wherein each laminated layer comprises two material layers with different refractive indexes and is used for filtering other optical signal components in an incident optical signal, each sample gathering unit is used for gathering a sample of a biological material, and the sample of the biologicalmaterial can generate an