DNA electrochemical sensor for detection of PRSS1 point mutation based on restriction endonuclease technique

To construct a restriction endonuclease based biosensor technology for PRSS1 genotyping. We designed a thiol-modified hairpin probe where the neck has EcoRI endonuclease recognition sites according to the PRSS1 gene c.410 C>T (p.T137 M) mutation and it was fixed on the gold electrode. Different charge generated by the binding of MB to phosphate groups of DNA before and after hybridization was used for distinguishing the different genotypes and quantity. This showed that the novel sensor can better distinguish the complementary sequence, single-base mismatches, and completely noncomplementary sequences, and the linear range for the logarithm was Y=-0.0242 X+0.1574, R=0.9912(Y=current, X=log target DNA concentration); the detection limit for DNA detection is estimated to be 50 fM.