Mesoporous carbon microparticles as a novel fluorescent sensing platform for thrombin detection

The present paper presents the novel use of MC microparticles (MCMPs) as a novel fluorescent sensing platform for thrombin detection. The MCMPs were prepared by a nanocasting method using mesoporous silica (MS) NPs as a hard template. The general concept used in this approach lies in the facts that the non-covalent adsorption of the dye-labeled TA on MCMP driven by π–π stacking of DNA bases on MCMP leads to substantial quenching of dye fluorescence due to their very close proximity. However, the presence of target TB results in the change of TA conformation to quadruplex due to the quadruplex–TB complex formation. Because the binding between the complex and MCMP is not strong enough to guarantee the close proximity of dyes to MCMP surface, fluorescence quenching is suppressed. This sensing system has a low detection limit down to 0.25 nM and exhibits excellent selectivity. We also demonstrate its application in human blood serum system.