Autotolerant ceruloplasmin based biocathodes for implanted biological power sources

Area of Science:

• Biochemistry
• Electrochemistry
• Bioelectrodes

Background:

• Human ceruloplasmin (HCp) is a blue multicopper oxidase found in human plasma.
• HCp exhibits a high redox potential and can directly reduce oxygen to water.
• Compared to other oxidases, HCp elicits a reduced inflammatory response in human blood.

Purpose of the Study:

• To investigate the bioelectrocatalytic activity of partially purified HCp for oxygen reduction.
• To evaluate HCp's potential as a biocatalyst in bioelectronic devices and biofuel cells.

Main Methods:

• Partial purification of HCp to maintain native conformation and activity.
• Immobilization of HCp onto nanostructured graphite electrodes.
• Amperometric studies at physiological pH and temperature in both mediated and non-mediated systems.

Main Results:

• Demonstrated direct electron transfer-based O2 bioelectroreduction by HCp for the first time.
• Achieved low reductive current densities of approximately 1.65 µA cm⁻² (non-mediated) and 12 µA cm⁻² (mediated).
• Confirmed reduced inflammatory response of HCp in human blood.

Conclusions:

• Partially purified HCp can perform O2 bioelectroreduction via direct electron transfer.
• Current bioelectrocatalytic performance of HCp is insufficient for practical application in biofuel cell cathodes.
• Further optimization is needed to enhance HCp's efficiency for bioelectronic device applications.