Polypyrrole merged zirconium-based metal-organic framework NU-1000 for detection of levodopa

A post-synthetic integration of polypyrrole onto NU-1000 MOF (PPy@NU-1000) was done by pyrrole adsorption, followed by oxidative polymerization. The synthesized materials were characterized by XRD, SEM, BET, and FTIR. The ultra-high specific surface area with high-density catalytic sites of NU-1000 (2223 m(2) g(-1)) was combined with the electrical conductivity of PPy (2-100 S cm(-1)). PPy@NU-1000 provides superior electrocatalytic activity and charge transfer properties compared to an individual component. The PPy@NU-1000-modified GCE was applied to detect the biomolecule Levodopa (LD). The DPV oxidation peak of LD was strongest at 27210 mV vs. Ag/AgCl reference electrode. Under the optimized experimental condition, the fabricated electrochemical sensor exhibited a wide quantification range of 0.005-70 mu M with a sub-nanomolar detection limit of 0.0001 mu M (S/N 3). The described sensor exhibits high sensitivity (2.08 mu A mu M-1 cm(-2)) with reasonable stability, reproducibility, and selectivity for the detection LD in the presence of potentially interfering compounds. Furthermore, human serum analysis showed excellent recovery values within the range 99.3-101.6%. Validation of the method was performed against HPLC.Graphical abstract