Microwave sensing of pM concentration of Insulin in buffer solution using WGM-DR

In this paper we describe a Whispering gallery mode (WGE₈₀₀) dielectric resonator method with a cheap polycarbonate sample holding disk for sensing variation in picomolar (pM) concentration of Insulin in hepes buffer solution. For investigation of pM concentration Insulin solution mainly three different volumes i.e. 0.4, 0.8 and 6.4 microliter volume of sample solutions loaded on sample holding disk (SHD) and analyzed. Obtained results shows that calculated loss tangent of solution is sensitive to variation in pM concentration of Insulin with no shift in frequency. Moreover, small response time, low sample volume and its ability to sense losses in pM concentration of Insulin in liquid medium makes this method ideal insulin biosensor for medical diagnostic purpose.