Surface Plasmon Resonance Immunosensor for Anionic Surfactants Based on an Indirect Competitive Immunoreaction

Abstract

A highly sensitive surface plasmon resonance immunosensor for the determination of linear alkylbenzene sulfonate (LAS) was fabricated. The method is based on an indirect competitive reaction of an anti‐LAS antibody in a sample solution with LAS immobilized on a sensor chip and with LAS in the sample solution. A sensor chip immobilized with LAS was prepared by utilizing an electrostatic interaction between an LAS conjugate, LAS–horseradish peroxidase (LAS‐HRP), and a self‐assembled monolayer of 11‐amino‐1‐undecanethiol hydrochloride, which was preliminary prepared on a gold thin film of the sensor chip. The quantitative determination of LAS in the concentration range 10–1000 ppb was achieved by using the proposed immunosensor.

Keywords:

• Surface plasmon resonance (SPR), self‐assembled monolayer, linear alkylbenzene sulfonate (LAS), anionic surfactants, LAS–horseradish peroxidase conjugate, indirect competitive immunosensor