A new electrochemical DNA biosensor based on the density control strategy of Ti3C2NH2 MXene@Au nanocomposites for the detection of hepatitis B virus-DNA

Viral hepatitis caused by hepatitis B virus is widespread, highly infectious, and difficult to cure, so it has become a concern of global public health security. Therefore, a convenient and rapid hepatitis B virus-deoxyribonucleic acid (HBV-DNA) test is the key to the treatment and prevention of these diseases. In this work, we prepared few-layered amino-functionalized Ti3C2Tx MXene (Ti3C2NH2 MXene) by etching with LiF/HCl etchant solution, and then the gold nanoparticles (Au NPs) were reduced to its surface to obtain Ti3C2NH2 MXene@Au and constructed a super-sensitive electrochemical DNA biosensor for rapid detection of HBV-DNA. The amount of - NH2 on the surface of Ti3C2NH2 MXene was regulated by controlling the pH value at the time of stripping, and the anchoring of gold nanoparticles was achieved by Au - N, which was used to regulate the number of gold nanoparticles on the surface of Ti3C2NH2 MXene; thus, the purpose of control the density of p-DNA was achieved. The composition and morphology of the Ti3C2NH2 MXene were characterized by field-emission scanning electron microscope (FSEM), transmission electron microscope (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR). The Ti3C2NH2 MXene@Au nanocomposite DNA sensor has the advantages of high sensitivity, good stability, and strong specificity, showing a wide detection range (1.0 x 10(-17)-1.0 x 10(-7) M) and a low detection limit (1.05 x 10(-14) M). The detection of HBV-DNA fragments can be realized in an artificial serum environment.