The enhancement method of optical fiber biosensor based on surface plasmon resonance with cold plasma modification

Cold plasma modification on optical fiber biosensor based on surface plasmon resonance (SPR) is proposed to enhance the SPR effect on biosensing. A side-polished multimode fiber sensor based on surface plasmon resonance as the transducing element with a halogen light source is carried out for the measurement of the BSA for the sensitivity analysis. The comparison with detection surface was fabricated by binding chemically to self-assembly monolayer (SAM) of 11-mercaptoundecanoic acid (MUA) and cold plasma modification method on gold (Au) surface of optical fiber, and then was activated by EDC/NHS for BSA. The pretreatment of cold plasma modification using isopropanol (IPA) to deposited carboxyl group on side-polished surface of optical fiber biosensor, and there are easily to combine biomolecule by EDC/NHS modification. The results of the comparison between traditional surface modification and cold plasma modification with the measurement for 5 ng BSA is observed on OSA and shifted obviously in wavelength. The side-polished fiber sensor based on surface plasmon resonance can provide the SPR response on spectrum, and the IPA plasma treatment can increase the sensitivity of the SPR dip shifted with 10–40 nm under the 10 min treatment time of the surface modification.