Label-free microcantilever-based immunosensors for highly sensitive determination of avian influenza virus H9

Abstract

We report on label-free immunosensors for the highly sensitive detection of avian influenza virus. The method makes use of the microcantilevers of an atomic force microscope onto which monoclonal antibodies against avian influenza virus were covalently immobilized. The factors influencing the performance of the resulting immunosensors were optimized by measuring the deflections of the cantilever via optical reflection, and this resulted in low detection limits and a wide analytical range. The differential deflection signals revealed specific antigen binding and their intensity is proportional to the logarithm of the concentrations of the virus in solution. Under optimal conditions, the immunosensors exhibit a linear response in the 7.6 ng mL−1 to 76 μg mL−1 concentration range of avian influenza virus, and the detection limit is 1.9 ng mL−1. FigureLabel-free immunosensors based on microcantilevers of an atomic force microscope was fabricated by covalently immobilizing monoclonal antibodies to avian influenza virus onto the microcantilever. The performance and factors influencing the performance of the resulting immunosensors were investigated in detail by measuring the cantilever deflections using the optical reflection technique. Electronic supplementary materialThe online version of this article (doi:10.1007/s00604-013-1129-x) contains supplementary material, which is available to authorized users.