This is new approach for biomolecule detection with label free method. The designed LC resonator by the combining inductors and capacitors was fabricated by MEMS process. The measured signal difference was 1.86 dB at 2.2 GHz between the return losses of biotin and avidin. The impedances for a bare device, biotin and avidin steps were Zo*(0.803-j0.002), Zo*(0.761-j0.003) and Zo*(0.718-j0.002) according to the Smith chart, respectively. From the mentioned data, we conclude that there is no frequency shift and the return loss variation at resonance point is distinctly large. This means that the biomolecule acts as a resistance, and the decreased resistance of the resonator leads to the impedance match change.