Tailored DNA nano-framework-enabled Medusa electrochemiluminescence immunosensor for quantitative detection of histone acetyltransferase

A novel Medusa electrochemiluminescence (ECL) immunosensor for quantitative detection of histone acetyltransferase (HAT p300) is designed and built well based on magnetic gold nanoparticles (Au-Fe 3 O 4 NPs), DNA nanonets and terminal deoxynucleotidyl transferase (TdT)-triggered renascent DNAs containing abundant A and T (named as AT-dsDNAs). Firstly, Au-Fe 3 O 4 NPs and substrate peptides are coated with the bare electrode surface one after the other. As the acetylation reaction happens, DNA nanonets, which are synthesized via Y-shape DNA (as building block) and acetyl antibody (Ab Ac )-grafted dsDNA (as crosslinker), are attached on the electrode surface. Next, AT-dsDNAs are formed under NaCl condition by TdT catalysis, in where deoxyadenosine triphosphate (dATP) and deoxythymidine triphosphate (dTTP) (half and half) can be added ceaselessly to countless 3′−OH of DNA nanonets. Abundant Ru(phen) 3 2+ molecules, which can be integrated well into high-level DNA nanomaterials above, serve as ECL luminophore in our biosensing. Only being HAT p300, an outstanding ECL response occurs favorably, and a detection limit of 0.0029 nM is acquired with a linear response in the range of 0.006–60 nM. The Medusa immunosensor with improved sensitivity presents a promising and possible widely use for the HATs-relevant clinical study and drug development.