Stochastic Binding Dynamics of a Photoswitchable Single Supramolecular Complex.

In this work, a real-time precise electrical method to directly monitor the stochastic binding dynamics of a single supramolecule based on the host-guest interaction between a cyclodextrin and an azo compound is reported. Different intermolecular binding states during the binding process are distinguished by conductance signals detected from graphene-molecule-graphene single-molecule junctions. In combination with theoretical calculations, the reciprocating and unidirectional motions in the trans form as well as the restrained reciprocating motion in the cis form due to the steric hindrance is observed, which could be reversibly switched by visible and UV irradiation.

An accurate, high-speed, portable bifunctional electrical detector for COVID-19.

Unlabelled: Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2, has rapidly spread and caused a severe global pandemic. Because no specific drugs are available for COVID-19 and few vaccines are available for SARS-CoV-2, accurate and rapid diagnosis of COVID-19 has been the most crucial measure to control this pandemic. Here, we developed a portable bifunctional electrical detector based on graphene fieldeffect transistors for SARS-CoV-2 through either nucleic acid hybridization or antigen-antibody protein interaction, with ultra-low limits of detection of ~0.

Label-Free Dynamic Detection of Single-Molecule Nucleophilic-Substitution Reactions.

The mechanisms of chemical reactions, including the transformation pathways of the electronic and geometric structures of molecules, are crucial for comprehending the essence and developing new chemistry. However, it is extremely difficult to realize at the single-molecule level. Here, we report a single-molecule approach capable of electrically probing stochastic fluctuations under equilibrium conditions and elucidating time trajectories of single species in non-equilibrated systems.

Building nanogapped graphene electrode arrays by electroburning.

Carbon nanoelectrodes with nanogap are reliable platforms for achieving ultra-small electronic devices. One of the main challenges in fabricating nanogapped carbon electrodes is precise control of the gap size. Herein, we put forward an electroburning approach for controllable fabrication of graphene nanoelectrodes from preprocessed nanoconstriction arrays.