Electro-immuno sensing device

An electro-immuno sensor includes a signal generator, a sensing chip and a sensing circuit. The signal generator is arranged for generating an electronic signal having a predetermined frequency and a waveform. The sensing chip is disposed in an electrical field that generates the electronic signal, and arranged for capturing target biomolecules in a solution using antibodies. The sensing circuit has a first electrode and a second electrode in contact with the solution, and arranged for measuring an electrical characteristic of a first state and the electrical characteristic of a second state between the first and second electrodes, due to the capture of the target biomolecules, and determining the concentration of the target biomolecules according to the variation of the electrical characteristic.