Studies On Gold Nanorod Labeled Optical Nanofiber Biosensors

Optical fiber evanescent sensor has attracted attention in the field of biosensor,with the advantages of high sensitivity,simple structure,low cost and small volume.With the development of micro fabrication technology and fiber transmission theory,researchers have focused on the practical use of this powerful biosensor.Now the main problems lie in the repeatability and specificity of Optical fiber biosensor.In this dissertation,sensing mechanism and manufacturing technology of bionical optical nanofiber was studied.A new structure of microfiber coupler has been proposed to solve the problem of repeatability.Optical nanofiber sensor based on gold nanorod is reported to enhance the specificity of this biosensor.The accomplished word and conclusions are as follows:(1)The transmission porperties and mode characteristics were studied.Factors contribute to the loss mechanism of biconical optical fiber were analyzed.A simple version of biconical optical fibe fabrication system was set up.The proper size and shape optical fibers were fabricated using heat-drawing system.(2)A new structure of microfiber coupler has been proposed to solve the problem of repeatability with the single bionical optical fiber.The repeatability,sensitivity and regeneration of microfiber coupler were studied.This biosensor has been used to detect the PSA,with limits of detection of 10 pg/m L. This biosensor can be regenerated for many times for the detection of goat-IgG.(3)Optical nanofiber sensor based on gold nanorod is reported to enhance the specificity of this biosensor.A model for calculating the optical loss caused by gold nanorod was built.Single gold nanorods with 20×50 nm were detected. The sensitivity and specificity of this biosensor were studied.A sandwich structure was used to detect the goat-IgG in PBS,with limits of detection of 0.02 ng/mL.