Novel surface plasmon resonance sensor chip functionalized with organic silica compounds for antibody attachment

Abstract

A novel method was developed for the fabrication of a surface plasmon resonance (SPR) sensor chip. A glass chip was covered with a gold layer which was then functionalized with gamma-aminopropylethoxysilane. Biomolecules could then be immobilized on the surface of the sensor using standard techniques. The sensor chip was found to be useful for highly sensitive SPR measurements using even smaller amounts of antibody than usual. The chip was found to be useful for the immobilization of anti-human serum albumin (anti-HSA) and anti-atrazine antibody, and was used for the SPR measurement of HSA and enzyme-labeled atrazine. The chip showed higher responses at both 10 and 100 mg l −1 HSA than a commercially available model. The relative standard deviation (RSD) of the responses was 7% for both concentrations of HSA ( n=8). A monoclonal antibody for atrazine was immobilized on the chip and 0.05 μg l −1 atrazine was measured with a RSD of 7% ( n=5). Atrazine was determined after addition to river water; 0.05 μg l −1 atrazine was detected with a very similar response as a standard atrazine solution of the same concentration.