Real-time detection of BSA concentration based on a Mach-Zehnder interferometric biosensor

A label-free optical fiber biosensor based on a Mach-Zehnder interferometer for real-time bovine serum albumin (BSA) concentration detection has been proposed and experimentally demonstrated. An air microcavity has been fabricated by means of splicing a segment of microfiber between two single mode fibers (SMFs) with appropriate offset such that it acts as a microfluidic channel, where external media can directly interact with the guided light. Experimental results show a high sensitivity of -15.56 nm/(mg/mL).