Design and fabrication of a novel platform for detection of 5-fluorouracil the anti-cancer drug using COFs/MOFs nanocomposite with graphene quantum dots

In this study, a novel modified electrode based on the covalent organic frameworks (COFs) Schiff base network-1 (SNW-1) hybridized with copper-based metal-organic frameworks (Cu-MOFs) embedded by graphene quantum dots (GQDs) nanocomposite at the glassy carbon electrode, SNW-1/Cu-MOFs/GQDs/GCE, was reported. The purpose of this modification is to enhance the detection capabilities of the constructed modified electrode for the 5-Fluorouracil (5-FU), an anti-cancer drug, by increasing its electrocatalytic activity towards the oxidation of 5 FU molecules. The SNW-1/Cu-MOFs/GQDs nanocomposite was effectively characterized by the various physicochemical analyses techniques including field emission scanning electron microscopy, energy dispersive X-ray spectroscopy, tunneling electron microscopy, Brunauer-Emmett-Teller (BET), X-ray powder diffraction and electrochemical methods. Electrochemical studies showed that the modified electrode, SNW-1/Cu-MOFs/GQDs/ GCE, has better electrocatalytic performance for oxidizing of the 5-FU compared to the unmodified GCE, GQDs/ GCE, SNW-1/GCE, Cu-MOFs/GCE and SNW-1/Cu-MOFs/GCE. This enhancement can be attributed to large surface area, good electrical conductivity, enhanced electron transport capability of the SNW-1/Cu-MOFs/GQDs and also synergistic effect of the SNW-1/Cu-MOFs with GQDs. In optimized conditions, the SNW-1/Cu-MOFs/ GQDs/GCE sensor demonstrates excellent properties including a wide linear response ranges (0.01-32 and 32-65 mu M), low detection limit (35 nM), high sensitivity (3.8 mu A mu M-1cm2),-1 cm 2 ), long-term signal stability, and reproducibility. It is worth noting that this sensor can accurately determine 5-FU in biological sample, showcasing its potential for practical analysis.