Eu-doped Gd2O3 nanoparticles as reporters for optical detection and visualization of antibodies patterned by microcontact printing

• Published in: Analytical and bioanalytical chemistry 2006-02, Vol.384 (3), p.631-637
• Main Authors: Nichkova, Mikaela, Dosev, Dosi, Perron, Richard, Gee, Shirley J, Hammock, Bruce D, Kennedy, Ian M
• Format: Article
• Language: English
• ISSN: 1618-2642; 1618-2650
• DOI: 10.1007/s00216-005-0246-8

Lanthanide oxide nanoparticles are promising luminescent probes in bioanalysis, because of their unique spectral properties, photostability, and low-cost synthesis. We report for the first time the application of europium-doped gadolinium oxide (Eu:Gd2O3) nanoparticles to the optical imaging of antibody micropatterns. The nanoparticles were synthesized by spray pyrolysis and coated with antibody (IgG) molecules by physical adsorption. Our experiments showed that the Eu:Gd2O3 is a good biocompatible solid support for antibody immobilization. The antibodies (anti-rabbit IgG) immobilized on the nanoparticles had excellent biological activity in the specific recognition reaction with rabbit IgG patterned in line strips (10 mumX10 mum) on a glass substrate by use of a micro-contact printing technique. The specific immunoreaction was confirmed by two independent microscopic techniques-fluorescence and scanning electron microscopy (SEM). Both microscopic images revealed that the nanoparticles were organized into designated structures as defined by the microcontact printing process with negligible non-specific binding. The nanoparticles can be used as fluorescent markers in a variety of immunosensing applications in a microscale format.