Molybdenum oxide-based metal-organic framework/polypyrrole nanocomposites for enhancing electrochemical detection of dopamine.

To overcome the poor conductivities and promote the application in the biosensors of metal-organic frameworks (MOFs), a simple approach was employed to improve their overall conductivity by adjusting the metal centers of MOFs and coating conductive polypyrrole (PPy) in the work. An unprecedented molybdenum oxide-based three-dimensional MOFs with helical channels (CuTRZMoO 4) was synthesized based on MoO 4 −, Cu2+ ions and 1,2,3-trz for the first time, then combined with PPy to fabricate hybrid composites (CuTRZMoO 4 @PPy-n) with both advantages. The CuTRZMoO 4 modified glassy carbon electrode show high sensitivity for detecting the neurotransmitter dopamine (DA), and the CuTRZMoO 4 @PPy-2 modified glassy carbon electrode has the highest catalytical activity to DA with the linear detection range from 1 μM to 100 μM and the detection limit of 80 nM (S/N = 3) by differential pulse voltammetry (DPV). Moreover, the developed biosensor has good selectivity, reproducibility and stability. The concept behinds the new architecture to modify electrodes should promote the further development of MOF-based biosensors. A high active, non-noble MOF based biosensing platform by adjusting the metal centers of MOFs and employing conductive polypyrrole (PPy) for enhancing detection of dopamine (DA) was developed for the first time. Image 1 • Molybdenum oxide-based metal-organic framework ([Cu 3 (trz) 2 (MoO 4) 2 ]·H 2 O) were synthesized. • Adjusting the metal centers of Mo based MOFs and employing conductive PPy to dopamine (DA) detection is discussed. • The CuTRZMoO 4 @PPy exhibit the excellent detection of DA with wide linear detection range and very low limit of detection. [ABSTRACT FROM AUTHOR]