Boron Doped Diamond Electrodes for Direct Measurement in Biological Fluids: An In Situ Regeneration Approach

Boron doped diamond (BDD) electrodes are extremely promising in the field of biomedical applications as they exhibit a unique combination of properties. Despite these advantages, BDD electrodes are prone to fouling when used in biological fluids (urine, blood plasma), and synthetic fluids. We propose a electrochemical (EC) treatment where a train of short cathodic and/or anodic pulses are applied to clean fouled electrodes. This technique can be used to retrieve the lost reactivity, characterized by electron transfer rate k0 of the boron doped diamond electrodes, thereby enhancing their reusability over long period of measurements without degradation of the signal, thus significantly extending the field of monitoring and surveying applications. The technique does not require the use of a specific medium and thus can be directly performed in the probed fluid. Although an aqueous electrolyte containing non-electroactive species is preferred for EC activation, it can also be done in biological fluids such as blood, urine etc, thereby opening the field for $in-vivo$ analysis. Through Electrochemical impedance spectroscopy (EIS) it was observed that the k$_0$ value was increased up to 0.1 cm s$^{−1}$ after the activation process. This technique improves the sensitivity, reproducibility and lifetime of the electrodes to a considerable extent.