Ultrasensitive and selective molecularly imprinted electrochemical oxaliplatin sensor based on a novel nitrogen-doped carbon nanotubes/Ag@cu MOF as a signal enhancer and reporter nanohybrid

A sensitive and selective molecular imprinted polymeric network (MIP) electrochemical sensor is proposed for the determination of anti-cancer drug oxaliplatin (OXAL). The polymeric network [poly(pyrrole)] was electrodeposited on a glassy carbon electrode (GCE) modified with silver nanoparticles (Ag) functionalized Cu-metal organic framework (Cu-BDC) and nitrogen-doped carbon nanotubes (N-CNTs). The MIP-Ag@Cu-BDC /N-CNTs/GCE showed an observable reduction peak at -0.14 V, which corresponds to the Cu-BDC reduction. This peak increased and decreased by eluting and rebinding of OXAL, respectively. The binding constant between OXAL and Cu-BDC was calculated to be 3.5 +/- 0.1 x 10(7) mol(-1) L. The electrochemical signal (Ai) increased with increasing OXAL concentration in the range 0.056-200 ng mL(-1) with a limit of detection (LOD. S/N= 3) of 0.016 ng mL(-1). The combination of N-CNTs and Ag@Cu-BDC improves both the conductivity and the anchoring sites for binding the polymer film on the surface of the electrode. The MIP-based electrochemical sensor offered outstanding sensitivity, selectivity, reproducibility, and stability. The MIP-Ag@Cu-BDC /N-CNTs/GCE was applied to determine OXAL in pharmaceutical injections, human plasma, and urine samples with good recoveries (97.5-105%) and acceptable relative standard deviations (RSDs = 1.8-3.2%). Factors affecting fabrication of MIP and OXAL determination were optimized using standard orthogonal design using 1.25 (5(6)) matrix. This MIP based electrochemical sensor opens a new venue for the fabrication of other similar sensors and biosensors.

Automated summary

A sensitive and selective molecular imprinted polymeric network (MIP) electrochemical sensor was developed for the determination of anti-cancer drug oxaliplatin (OXAL). The sensor showed outstanding sensitivity, selectivity, reproducibility, and stability, with optimized fabrication processes and orthogonal design techniques. This MIP-based sensor opens up new possibilities for the fabrication of similar sensors and biosensors.