Adenosine triphosphate detection by controlled-release of carboxy fluorescein from mesoporous silica nanoparticles blocked with aptamer-based gold nanoparticles

In this paper, an adenosine-5′-triphosphate ( ATP ) controlled-release strategy to construct a fluorescence sensing platform has been designed. In the sensing platform, because of ATP aptamer and singlestranded DNA ( ssDNA )-linked mesoporous silica nanoparticles ( Si-MPs ) were hybridized, the pores of Si-MPs were blocked with Au nanoparticles ( AuNPs ) modified with ATP aptamer. Carboxy fluorescein was plugged in channels of Si-MPs. In the presence of target molecule ATP, the ATP aptamer combined with ATP and the AuNPs got away from the pore of the surface of Si-MPs modified by ssDNA. 5-Carboxyfluorescein molecule was released to allow the fluorescent detection. By monitoring the fluorescence at 518 nm, ATP could be quantitatively detected with a detection limit of 6 × 10 –8 M. The linear response range was 6 × 10 –8 to 1 × 10 –6 M. This assay was also able to discriminate ATP from its analogs. The controlled-release aptamer-based biosensor could have an effective application in human breast cancer MCF-7 cells.