Hollow fiber SPR sensor available for microfluidic chip

We propose and demonstrate a dual-channel surface plasmon resonance (SPR) sensor based on a microstructured hollow fiber (MHF), which is available for microfluidic chips. Two channels contain an internal sensing channel inside of the MHF due to the hollow structure, and an external sensing channel outside of the MHF. We employ a fiber grinding-polishing & butt-jointing technology to configure the hollow fiber SPR sensing probe. We plate the gold coatings on the internal and external sensing channels with the thickness of 50 nm, respectively. When the refractive index of the testing samples is in the range of 1.333-1.385, the range of resonance wavelengths in the internal sensing channel is 712nm-1010 nm, and the range of resonance wavelengths in the external sensing channel is 618nm-700 nm. The testing sensitivity of the internal sensing channel is 5645 nm/RIU and testing sensitivity of the external sensing channel is 1576 nm/RIU. Due to the special structure of the MHF, where an air hole in the MHF, the hollow fiber SPR sensor has the superiority of being easy to be multiplexed in a microfluidic chip system.