Multiwalled carbon nanotubes modified with nickel-zinc bis(dithiolene) metal-organic frameworks for electrochemical detection of 5-hydroxytryptamine

5-hydroxytryptamine (5-HT) is an important neurotransmitter that plays an important role in regulating mood, sleep, vomiting, cardiovascular function, libido and appetite. When its concentration level changes or exceeds a certain range, it can lead to a variety of diseases. In this study, bis (dithiophen-dibenzoic acid) nickel, [Ni(C2S2(C6H4COOH)2)2], was successfully synthesized and self-assembled with Zn(NO3)2·4H2O to form a oxidation–reduction active three-dimensional MOFs with a nickel-zinc bimetallic center. Multi-walled carbon nanotubes (MWCNTS) have good electrical conductivity, and the composite of 3D Ni Zn-MOF materials with unsaturated coordination and oxidation–reduction activity can improve the electrical conductivity and catalytic performance of the composite. The prepared Ni Zn-MOF/MWCNTs/GCE electrochemical sensor can be used for detecting 5-HT. Under the optimized conditions, the concentration range of 5-HT was 0.5–115 μM, and the detection limit (LOD) was 0.03 μM (S/N = 3). The recovery of 5-HT in urine samples was 99.94 % ∼ 102.02 %, which proved that the sensor has excellent practical application value.