Abstract
We fabricated a sensitive and selective electrochemical carbon monoxide (CO) sensor for physiological conditions based on the Pt-Ru system. At a bare Pt-Ru electrode, a linear amperometric response to CO concentration was obtained in the range of 0.9 – 9 μM. However, significant current response to model electroactive interferents for physiological conditions, uric acid (UA), ascorbic acid (AA) and hydrogen peroxide (HP), was also recorded at the Pt-Ru electrode. The response to UA and AA was highly suppressed by coating the Pt-Ru electrode surface with a Nafion layer, and the response to HP was almost completely eliminated by the additional coating with a MnO2/chitosan layer. Finally, at the Pt-Ru/Nafion/MnO2 electrode, amperometric CO detection with a sensitivity of 173 nA cm−2 μM−1 was obtained in the concentration range of 0.9 – 9 μM with the UA, AA and HP signal being below 1.7% at the same concentration of CO.
