A novel electrochemical DNA sensor was designed to detect Helicobacter pylori based on accordion-like Ti3C2Tx. Here the multilayer Ti3C2Tx obtained by DMSO delamination was used to modify the glass carbon electrode, with a large specific surface area and excellent conductivity. Au nanoparticles were supported on the modified electrode and worked as an effective carrier to fix the capture probe (cpDNA) with sulfhydryl group through the firm binding of Au-S bond. Such an accordion-like Ti3C2Tx structure provides an ultrahigh electroactive surface area and ample binding sites for accommodating Au nanoparticles, which is advantageous for the signal amplification during the detection. And further, the sandwich structure formed by hybridizing cpDNA with target DNA sequence (tDNA) and rpDNA (rpDNA is a strand of DNA that can be base-paired with the tested tDNA) increases greatly the current signal and enhances the sensitivity of the electrochemical DNA sensor. Under optimal conditions, the developed electrochemical DNA sensor showed a wide linear range from 10-11 to 10-14 M and a low detection limit of 1.6 × 10-16 M and exhibited good sensitivity, reproducibility, and stability. A novel electrochemical DNA sensor with simple sandwich structure was designed to detect H. pylori based on accordion-like Ti3C2Tx.
Keywords: DNA; Electrochemical; Helicobacter pylori; Sensor; Ti3C2Tx.