Cholesterol as a Promising Alternative Energy Source: Bioelectrocatalytic Oxidation Using NAD-Dependent Cholesterol Dehydrogenase in Human Serum
Journal Article - Open Access
Departments of Chemistry and Materials Science and Engineering, University of Utah Salt Lake City United States
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Cholesterol is an essential structural component of mammalian cells, although elevated concentrations of cholesterol in the human body are linked to atherosclerotic disease. In this context, monitoring physiological cholesterol concentrations is of great interest in medical fields and the concept of producing electrical energy from cholesterol is interesting. In this work, we report the bioelectrocatalytic oxidation of cholesterol with the use of nicotinamide adenine dinucleotide-NAD dependent cholesterol dehydrogenase ChDH as an alternative enzyme to the commonly-used cholesterol oxidase ChOx in bioelectronic applications. To achieve bioelectrocatalytic cholesterol oxidation, ChDH was combined with diaphorase DH in a bilayer fashion, whereby DH acts as an intermediary enzyme to facilitate NADH oxidation at a ferrocene redox polymer. Characterization of the resulting bioanode identifies a linear cholesterol response range from 5 M to 200 M, with an associated sensitivity of 60.12 mA cm2 M1. Furthermore, an O2-reducing biocathode incorporating bilirubin oxidase BOx was combined with the cholesterol bioanode into a complete cholesterolO2 membrane-less enzymatic fuel cell EFC.
- Electrochemical Energy Storage