Figure 3.

Reversible HRP immobilization onto porous SiO₂surface using DDI and the corresponding enzymatic activity.(a) A schematic illustration of reversible enzyme immobilization onto PSiO₂ surface using DDI approach. Note: These schematics are for illustration purposes only as all modifications occur also inside the pores. (b) Relative activity of HRP immobilized via DDI onto PSiO₂. (c) Removal of the DNA-enzyme conjugates form the surface by mild dehybridization. Two consecutive cycles of DNA-enzyme hybridization/dehybridization are performed. (d) HRP enzymatic activity is quantified using the Ampliflu Red assay in which oxidation of the non-fluorescence Ampliflu substrate occurs in the presence of HRP and H₂O₂ to fluorescence resorufin.