Zinc Oxide-Carbon Cloth Nanosensors for Simultaneous Detection of Uric Acid, Epinephrine, and Ascorbic Acid

We present a flexible, inexpensive electrochemical sensor using zinc oxide (ZnO) grown directly on carbon cloth for the simultaneous detection of uric acid (UA), epinephrine (EP), and ascorbic acid (AA). The simultaneous detection of these biomolecules poses inherent challenges since their concentrations in the human body are low and the obtained signals are difficult to deconvolve. These limitations were overcome by using nanostructured ZnO on three dimensionally woven carbon fibers as a high surface area biosensing platform. Additionally, a differential pulse voltammetry (DPV) detection technique was used to overcome the bottleneck of clearly resolving signals from UA, EP and AA. The results obtained demonstrate the simultaneous detection of UA, EP and AA. The lowest simultaneously detected concentrations were 2.5 μM for UA, 4.0 μM for EP, and15 μM for AA, in the presence of the remaining two molecules at concentrations of 50 μM for UA and EP and 600 μM for AA. We have also successfully scaled down the biosensing platform to a single carbon fiber with ZnO to demonstrate similar results. Our results indicate that the prepared biosensor was robust, highly sensitive, and stable. Figure 1