MXene quantum dots enhanced 3D-printed electrochemical sensor for the highly sensitive detection of dopamine

Using 3D-printed electrochemical sensor for the detection of biomarker has aroused widely attentions in the field of disease diagnosis. Herein, 3D printing method was employed to print 3D-printed electrode (3DE) using graphene/polylactic acid (PLA) filament. Then, synthesized MXene quantum dots (MQDs) were dropped on the activated 3DE to construct a novel sensor for highly sensitive detection of dopamine (DA). The surface physical and chemical properties of the prepared 3DEs were measured by scanning electron microscope (SEM), X-ray photoelectric spectroscopy (XPS) and contact angle experiments. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods were also performed to research the electrochemical properties of the prepared 3DEs. The constructed sensor can be used to determine DA in the concentration from 0.01 to 20 μM with an ultra-low limit of detection (3 nM). Furthermore, the sensor was further applied to detect DA in practical sample with high selectivity. The enhanced 3D-printed sensor will open the new avenue for using QDs of 2D materials in 3D-printed electrodes.