A new electrochemical DNA biosensor based on the density control strategy of Ti 3 C 2 NH 2 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 Ti 3 C 2 T x MXene (Ti 3 C 2 NH 2 MXene) by etching with LiF/HCl etchant solution, and then the gold nanoparticles (Au NPs) were reduced to its surface to obtain Ti 3 C 2 NH 2 MXene@Au and constructed a super-sensitive electrochemical DNA biosensor for rapid detection of HBV-DNA. The amount of − NH 2 on the surface of Ti 3 C 2 NH 2 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 Ti 3 C 2 NH 2 MXene; thus, the purpose of control the density of p-DNA was achieved. The composition and morphology of the Ti 3 C 2 NH 2 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 Ti 3 C 2 NH 2 MXene@Au nanocomposite DNA sensor has the advantages of high sensitivity, good stability, and strong specificity, showing a wide detection range (1.0 × 10 −17 –1.0 × 10 −7 M) and a low detection limit (1.05 × 10 −14 M). The detection of HBV-DNA fragments can be realized in an artificial serum environment. Graphical Abstract