Bipolar Clark-Type Oxygen Electrode Arrays for Imaging and Multiplexed Measurements of the Respiratory Activity of Cells.

Various miniature Clark-type oxygen electrodes (COEs), which are typically used to measure dissolved oxygen (DO) concentration in cellular respiration, have been developed since the 1980s. Arrays with individually addressable electrodes that constitute the sensor were used for various applications. However, the large number of leads and contact pads required for connecting the electrodes and the external instrument complicate the electrode layout and make the operation of integrated COE arrays challenging.

Bipolar Electrode Arrays for Chemical Imaging and Multiplexed Sensing.

Bipolar electrodes (BPEs) with arrays of cathodic and anodic poles were developed for use in closed bipolar systems. To increase the number of BPEs in the array, the anodic and cathodic poles were connected with each other using thin leads. A further increase in the number of BPEs was achieved by forming the cathodic and anodic poles of the BPEs and the leads in different layers.

Wired Microfabricated Electrochemical Systems.

Metal wires have been used as an alternative to liquid junctions for the connection of solutions in microfabricated electrochemical devices. They exhibit similar performance to liquid junctions, provided that the interfacial potentials at both ends of the wires were appropriately canceled. Cyclic voltammograms of devices with liquid junctions and metal wires were very similar when no current or a low current flowed through the metal wire between the working and reference electrodes.

Microdevice with an Integrated Clark-Type Oxygen Electrode for the Measurement of the Respiratory Activity of Cells.

A microdevice for the measurement of the respiratory activity of cells was fabricated using a microfabricated Clark-type oxygen electrode. The oxygen electrode was completed in a dry state and was activated by introducing water necessary for the reduction of oxygen in the form of water vapor through an oxygen-permeable membrane, which significantly facilitated handling of the device even by nonspecialists. The use of a thin paper layer stabilized the current response and enabled stable continuous operation of the oxygen electrode without current disturbance caused by the evaporation of water.