Enzyme and voltage stimuli-responsive controlled release system based on β-cyclodextrin-capped mesoporous silica nanoparticles.

Enzyme and voltage stimuli are more biologically compatible in the field of stimuli-responsive systems and release systems based on β-cyclodextrin (CD) and ferrocene (Fc) have attracted much attention. Herein, mesoporous silica nanoparticles (MSNs) have been functionalized with the ferrocenyl moiety (Fc) which interacts with β-cyclodextrin (β-CD) to form an inclusion complex on the opening of the pores. The size of the inclusion complex results in a barrier to the opening of the pores. Based on these characteristics, MSNs with nanovalves have been developed as a release system. The release system shows a clear response to heme protein (horseradish peroxidase or hemoglobin) and H2O2, glucose oxidase (GOD) with horseradish peroxidase (HRP) and glucose, or +1.5 V based on an oxidation stimulus mechanism. Modulating the amount of enzyme or the discretion of the voltage makes the release system a controlled one.