A flexible electrochemical sensor based on Fe-doped polydopamine derived carbon for simultaneous detection of dopamine and uric acid

A free-standing electrode based on carbon cloth-supported Fe-doped polydopamine-derived carbon (Fe/PDA-C/CC) was developed for the simultaneous detection of dopamine (DA) and uric acid (UA). First, dopamine was self-polymerized on the surface of the carbon cloth to obtain polydopamine coatings. Subsequently, Fe³⁺ was introduced through the formation of a coordinate bond with the hydroxyl functional group in the polydopamine layer. After calcination, a flexible and free-standing electrode was obtained. The sensing performance and mechanism of the Fe/PDA-C/CC sensor was investigated and is discussed in detail herein. Experimental results demonstrated that Fe/PDA-C/CC could simultaneously detect DA and UA with a wide detection range of 0.5–300 μM and 0.5–400 μM with low detection limits of 0.041 μM and 0.012 μM, respectively. Meanwhile, Fe/PDA-C/CC possessed excellent anti-interference performance, repeatability, stability, and accuracy in real samples. Overall, this study provides a facile and effective approach for simultaneous detection of UA and DA.