All-fiber Optofluidic Biosensor

Optical fiber provides a unique and versatile platform for developing point-of-care optical sensing systems. Here we first propose a Fabry-Perot (FP) based flow-through optofluidic biosensor, and then construct an all-fiber system which fully utilizes optical fibers to achieve rapid, sensitive, label-free biomolecular detection. This sensor consists of two single mode fibers (SMFs) with reflecting surfaces and a photonic crystal fiber (PCF) vertically sandwiched by them. Firstly, the SMFs act as waveguides for delivering light into and out of an optofluidic device (like PCF); secondly, instead of using the optical properties of the PCF, we take advantage of its inherent multiple fluidic channels and large sensing surface; thirdly, the two reflective surfaces and the PCF form a Fabry-Perot microresonator and its resonance mode is sensitive to the change in the fluidic channels, which can be used to detect the substances flowing through the fluidic channels or adsorbing on the channel surface. In this paper, we explore the operating principle of the FP-based optofluidic biosensor, theoretically and experimentally investigate its feasibility and capability. The results show that the all-fiber optofluidic sensor is a promising technology platform for rapid, sensitive and high-throughput biological and chemical sensing.