DNA tweezers-controlled direct electrical contact of horseradish peroxidase on porous carbon nanotube substrate

The controlled direct electrical contact (DEC) of an enzyme with the electrode is vital to the design of a bio-electronic device. DNA scaffolds are controllable and programmable but using them to control the DEC of horseradish peroxidase (HRP) with electrodes has not been reported. In this work, porous carbon nanotubes (PCNT), which had excellent electron transfer capability, were synthesized and used as the electrode substrates for the DEC of HRP via target DNA-regulated DNA tweezers (DTs). Target DNA served as fuel can switch the DTs to regulate the distances between the enzyme and PCNT dynamically to control the electrons' transfer efficiency. Our work of direct, unmediated electrical "wiring" of enzymes on PCNT controlled by DTs precisely not only expanded the rule set of electrical contact of the enzyme but also had the potential to provide universal platforms to recognize other species through simply altering the related capture. We envision that our platform would inspire the development of artificial unmediated bio-controlled biosensors.