Non-enzymatic electrochemical voltammetric sensors based on thulium:zinc oxide for dopamine detection

In this study, zinc oxide (ZnO) powders with dopant rates of 1 mol% thulium (Tm) (1Tm:ZnO), 2 mol% Tm (2Tm:ZnO), and 3 mol% Tm (3Tm:ZnO) nanoparticles were synthesized by co-precipitation method. Subsequently, Polyaniline (PANI)/1Tm:ZnO, PANI/2Tm:ZnO, and PANI/3Tm:ZnO nanocomposite sensors were prepared using a low-cost and simple sonication method. The results showed that the prepared PANI/1Tm:ZnO-based biosensor detected dopamine in the concentration range of (0.8–6.5) µM with a sensitivity of 0.2568 µAµM−1cm−2. Using these sensitivity values of the sensor, the LOD and LOQ values of the PANI/1Tm:ZnO-based sensor were calculated as 1.92 µM and 5.8 µM, respectively. The incorporation of 1% Tm into ZnO host (PANI/1Tm:ZnO) significantly enhanced the sensitivity of the biosensors.