THz Bio-chemical Sensing Capabilities with High Performance SIW Based Sensor on nL-Volume Liquids in Capillary

Label-free and online bio-chemical detection proved to be possible with THz waves, which would open alternative ways to a myriad of applications in the chemical, biological and medical fields such as integrated micro-reactor monitors, PCR monitoring, faster and cheaper drug discovery. However some technological challenges need to be surmounted, especially low sensitivity and large sample quantity, before practical applications can be implemented. These challenges are tackled here by an integrated sensor approach, whereby a specially developed substrate integrated waveguide is used in combination with capillary tube to maximally exploit the dynamic range of the measurement system. The sensor performance is benchmarked with water/alcohol mixtures. A selection of measurements on biological substances is presented to demonstrate the bio-chemical sensing capabilities. The developed approach shows outstanding sensitivity performance for extremely small sample quantities.