▎ 摘　　要

NOVELTY - Manufacturing biosensor comprises growing graphene film on a copper foil and obtaining a graphene block, where the graphene block is attached with organic glass; removing the copper foil attached to the graphene film, moving the graphene film to the glass plate with indium tin oxide electrode as the bridge between the two electrodes, where two electrodes on the glass respectively serve as the source electrode and the drain electrode of the biosensor; covering the glass plate of the indium tin oxide transferred with the graphene on a channel of a digital micro-fluidic chip as the container for containing the solution to be tested; punching on the digital microfluidic chip, adopting the electrode in the hole as a gate input voltage to form an electric channel; where the excitation light source is conducted to the sensitive area through the optical fiber, forming an optical channel; and applying a periodic magnetic field to form a magnetic channel. USE - The detection method of the biosensor is useful for detecting DNA with different concentrations. ADVANTAGE - The biosensor has high specificity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) the biosensor, manufactured by the method, (2) a detection method of biosensor, and (3) a light electromagnetic system for recording the change of the electric signal change and the fluorescence intensity when the biosensor detects.