High-efficient preparation and screening of electrocatalysts using a closed bipolar electrode array system

Closed Bipolar Electrode Array for Optical Reporting Reaction-Coupled Electrochemical Sensing and Imaging

This review centers on a closed bipolar electrode (BPE) array using an electro-fluorochromism (EFC) or electro-chemiluminescence (ECL) reaction as the reporting reaction. Electrochemical signals at one pole of the closed BPE array can be transduced into the EFC or ECL signals at the opposite pole. Therefore, the current signal of a redox reaction can be easily detected and imaged by monitoring the luminescence signal. Recent developments in closed BPE array-based EFC and ECL sensing and imaging are summarized and discussed in detail. Finally, we consider the challenges and opportunities for improving the spatial resolution of closed BPE array-based electrochemical imaging, and emphasize the important application of this technique to the imaging of cellular activities at the single-cell level.

Coating Process Parameters and Structural Properties of the Tubular Electrodes of Fuel Cells Based on a Self-Made Coating Device

The electrode is one of the most important components of tubular direct methanol fuel cells (DMFC), and the coating process directly determines its performance. In the present research, a tubular electrode coating device was designed based on planetary gear structures, and the influence of the coating process parameters on the electrode structure’s performance was studied. The experimental results show that: the coating layer on the electrode surface prepared by the self-made device is uniform and dense, and the coating surface quality is better than a manual coating. The best coating environment temperature is 30–40 °C, and the coating spindle speed is 6.67 r/min. Under the condition in which Nafion 117 is used as the proton exchange membrane, the fuel cell is placed in 1 mol/L H2SO4 + 0.5 mol/L CH3OH electrolyte, and high-purity oxygen is fed at a rate of 100 mL/min, the power density of the electrode coated by the self-made device can reach 20.50 mW/cm2, which is about 2.4 times that of the electrode coated manually.

A portable electrochemiluminescence bipolar electrode array for the visualized sensing of Cas9 activity

CRISPR/Cas9 has become a powerful tool for genomic manipulation, and the evaluation of the Cas9 activity is essential for the precise control of the CRISPR system. Herein, we develop a point-of-care platform for the rapid and visible determination of the Cas9 activity. A bipolar electrochemiluminescence (ECL) biosensor platform comprises an Au electric circuit fabricated on a glass substrate and the PDMS layer acts as a reservoir. DNA probes are then modified on electrodes and hybridization chain reaction (HCR) is applied to introduce ferrocene-labeled DNA. The CRISPR/Cas9 system can recognize the immobilized DNA probes and cleave them from the electrode surface as well as the labeled H1 and H2. Therefore, the cleavage activity is closely related to the labeled ferrocene. The modified electrode is then embodied in a closed bipolar system such that the oxidation reaction on sensing poles could be detected by the anodic ECL reactions on isolated luminescent poles due to charge balance, leading to the changes in ECL signals. This portable, integrated and convenient platform may become a meaningful tool for the discovery of a new CRISPR/Cas9 system or additional Cas9 inhibitors.