Experimental demonstration of integrated photonic free-label biosensor for CBRN threats using micro-ring resonators

In this work, we present integrated photonic sensor design to detect Chemical, Biological, Radiological and Nuclear (CBRN) threats, where high sensitivity and no false positive are strictly required. The sensor is formed by several parallel micro-ring resonators exposed to the environment and functionalized to recognized target analytes in a free-label way. Experimental demonstration of the working principle was performed using simulant compounds that permit tests of the features of the Photonic Integrated Circuit (PIC) in a safe environment. The results show the possibility of using PICs to detect as low as 20 ppb of Ovalbumin (simulant for Ricin A toxin) and 200 CFU/ml of Bacillus cereus spores (simulant for Bacillus anthracis). These results push forward the possibility of using PICs as biochemical sensors, also for critical objectives.