In this paper, a microfluidic sensor structure has been proposed for operating frequency reconfiguration purpose. The structure has been designed by using split ring resonator architecture with a transmission line. 0%, 20, 40%, 60%, 80% and 100% ethanol volume content in the ethanol-water mixture have been used as samples to understand sensing characteristic of the proposed structure. After that five sensor structure with different dimension coefficients (1.4, 1.2, 1, 0.8 and 0.6) are designed and manufactured. The ethanol-water mixture samples has been applied to the sensor structure and it is observed that there is a linear relation operating frequency band and the dimension coefficient. The study has been realized both numerically and experimentally and the results are in a good agreement. The proposed structure is a good candidate for microfluidic sensing applications and operating frequency band of the structure can be easily reconfigured any necessary and desired range with respect to electrical characteristics of the samples.