Electrochemical\nPlatform Based on the Bi<sub>2</sub>Te<sub>3</sub> Family of Topological\nInsulators for the Detection\nof SARS-CoV‑2 Pathogenic Factors

Accurate and rapid detection of the causative agent of\na disease\nis of great importance in controlling the spread of the disease. This\nwork developed a biosensor with the Bi<sub>2</sub>Te<sub>3</sub> family\nof topological insulators for detection of the SARS-CoV-2 virulence\nfactor. The Bi<sub>2</sub>Te<sub>3</sub> family is a three-dimensional\ntopological insulator material with topologically protected surface\nstates; the presence of these surface states facilitates charge transfer\nbetween the electrode and electrolyte interface. Compared with the\ndetection performance of Bi<sub>2</sub>Se<sub>3</sub>, BiSbTeSe<sub>2</sub>, and a trivial insulator like Sb<sub>2</sub>Se<sub>3</sub>, Bi<sub>2</sub>Te<sub>3</sub> exhibits superior characteristics.\nA Bi<sub>2</sub>Te<sub>3</sub> electrochemical detection platform\nis utilized to fabricate a sensor that can detect SARS-CoV-2 DNA,\nRNA, and antigen for label-free target detection. The concentration\nrange of DNA detection by the biosensor using Bi<sub>2</sub>Te<sub>3</sub> is between 1.0 × 10<sup>–15</sup> and 1.0 ×\n10<sup>–10</sup> M, and the detection limit can reach 1.41\n× 10<sup>–16</sup> M. Furthermore, it exhibits excellent\nselectivity and maintains good stability even after being stored for\n14 days. This study provides a new way to apply topological insulator\nmaterials in the field of biosensors and use their unique electronic\nstructure to improve the accuracy and speed of disease detection and\ndiagnosis.