Mesoporous silica templated biolabels with releasable fluorophores for immunoassays

Cai, W., Gentle, I.R., Lu, G.Q., Zhu, J-J and Yu, A. (2008) Mesoporous silica templated biolabels with releasable fluorophores for immunoassays. Analytical Chemistry, 80 (14). pp. 5401-5406.

Abstract

A novel class of fluorescent immuno-biolabeling systems with extremely high F/P ratio (1000−6000) were prepared by combining the template method and layer-by-layer (LbL) technique. Labels were constructed by loading organic dye fluorescein diacetate (FDA) molecules onto hollow periodic mesoporous organosilica (H-PMO) particles followed by ployelectrolyte encapsulation and antibody attachment. The labeling systems were stimuli-responsive to the addition of concentrated NaOH with the loaded dye molecules being released and detected in a well-controlled manner. When applied in sandwich immunoassays, results indicated that the biolabels were immuno-active and generated an optimal signal that was 50 times higher than the conventional dye labelled antibody system.