A Highly Sensitive Fiber-Optic Immunosensor Using a Metal-Complex Compound as a Chemiluminescent Catalyst

Abstract

Abstract A highly sensitive fiber-optic immunosensor using an antibody-immobilized optical fiber was developed and introduced into a chemiluminescence complex catalyst immunoassay (CLCCIA) which had been reported by the authors in a previous paper. After optimization of the experimental conditions, human serum albumin as model protein was determined by both competitive immunoassay and sandwich immunoassay, using the fiber-optic immunosensor. Human serum albumin could be determined in the concentration range 1×10−4–1×10−1 g dm−3 with a lower limit of 400 pg by competitive immunoassay while in the concentration range 1×10−5–1×10−1 g dm−3 with a lower limit of 40 pg by sandwich immunoassay. The new fiber-optic immunosensor developed by the authors can be characterized as follows: 1) Highly sensitive for the determination of a small amount of protein, 2) applicable to a wide concentration range of protein sample, 3) feasible with a microvolume of sample, 4) suitable for automated operation, and 5) excellent regarding safety, cost, and treatment.