Endonuclease-based logic gates and sensors using magnetic force-amplified readout of DNA scission on cantilevers

The endonuclease scission of magnetic particles functionalized with sequence-specific DNAs, which are associated on cantilevers, is followed by the magnetic force-amplified readout of the reactions by the nano-mechanical deflection/retraction of the cantilevers. The systems are employed to develop AND or OR logic gates and to detect single base mismatch specificity of the endonucleases. The two endonucleases EcoRI (E_A) and Ascl (E _B) are used as inputs. The removal of magnetic particles linked to the cantilever by the duplexes 1/1a and 2/2a via the simultaneous cleavage of the DNAs by E_A and E_B leads to the retraction of the magnetically deflected cantilever and to the establishment of the "AND" gate. The removal of the magnetic particles linked to the cantilevers by the duplex 3/3a by either E_A or E_B leads to the retraction of the magnetically deflected cantilever and to the establishment of the "OR" gate. The magnetic force-amplified readout of endonuclease activities is also employed to reveal single base mismatch specificity of the biocatalysts.