Time-reversal invariant resonant backscattering on a topological insulator surface driven by a time-periodic gate voltage

Sensitive biosensors based on topological insulator Bi2Se3 and peptide

In this work, we designed a facile and label-free electrochemical biosensor based on intrinsic topological insulator (TI) Bi₂Se₃ and peptide for the detection of immune checkpoint molecules. With topological protection, Bi₂Se₃ could have robust surface states with low electronic noise, which was beneficial for the stable and sensitive electron transport between electrode and electrolyte interface. The peptides are easily synthesized and chemically modified, and have good biocompatibility and bioavailability, which is a suitable candidate as the recognition units for immune checkpoint molecules. Therefore, the peptide/Bi₂Se₃ was developed as a suitable working electrode for the electrochemical biosensor. The basic performance of the designed peptide/Bi₂Se₃ biosensor was investigated to determine the Anti-HA Tag Antibody and PD-L1 molecules. The linear detection range was from 3.6 × 10^-10 mg mL^-1 to 3.6 × 10^-5 mg mL^-1, and the detection limit was 1.07 × 10^-11 mg mL^-1. Moreover, the biosensor also displayed good selectivity and stability.

Electrochemical DNA Biosensors Based on the Intrinsic Topological Insulator BiSbTeSe2 for Potential Application in HIV Determination

In this work, we reported a sensitive, label-free electrochemical biosensor based on the intrinsic topological insulator (TI) BiSbTeSe₂ for potential application in the determination of the HIV gene. With strong spin-obit coupling, TIs could have robust surface states with low electronic noise, which might be beneficial for the stable and sensitive electron transport between the electrode and electrolyte interface. Under optimized conditions of the biosensors using BiSbTeSe₂, the differential pulse voltammetry (DPV) peak currents showed a linear relationship with the logarithm of target DNA concentrations ranging from 1.0 × 10^-13 to 1.0 × 10^-7 M, with a detection limit of 1.07 × 10^-15 M. The sensing assay also displayed good selectivity and stability after storage at 4 °C for 7 days. This work provides an effective way to develop biosensors with topological materials, which have a potential application in the clinical determination and monitoring field.

Dual Dirac points and odd-even oscillated energy gap in zigzag chlorinated stanene nanoribbon

Stanene has been predicted to be a two-dimensional topological insulator, providing an ideal platform for the realization of quantum spin Hall effect even at room temperature. Based on first-principles calculations, we studied the topological edge states in zigzag chlorinated stanene nanoribbon. From our calculations, dual Dirac points can be found near Fermi level. One Dirac point is localized at the edges and emerges in a narrow nanoribbon, while another is widespread and can only be found in a wide nanoribbon due to the coupling of two opposite edges. At the localized Dirac point, there is an interesting odd-even oscillated energy gap with the change of the width of nanoribbon. The energy gaps at both Dirac points and the coupling of two opposite edges can be modified by edge adsorption. Asymmetric adsorption of two edges was also discussed. Our calculations may be helpful for the potential applications of tin-based topological nanoribbons in nanodevices.