Magnetic stirring hydroxylation for fabrication of a highly modulated Cu-intercalated 3D titanium aluminum carbide MXene network for efficient electrochemical detection of fluorouracil

Abstract

With the growing incidence of cancer, cytostatic drugs that block the growth of cancer cells are being increasingly consumed, raising concerns regarding pharmaceutical pollutants. Halogen-containing antineoplastic fluorouracil (FLU) residues are continuously released into environmental water and soil surfaces, and upon entering the environment, they cause carcinogenic risks to environmental organisms and are hazardous to human health. Thus, on-site monitoring devices must be designed to prevent such hazardous pollutants from spreading to water, land, and ecosystems. We used erosion hydroxylation to fabricate a Cu-intercalated titanium aluminum carbide (TAC) MXene (Cu-Ti3Al1-xC2-OHx or Cu-TAC-3) for the on-site monitoring of cytotoxic FLU in environmental samples. The three-dimensional Cu-TAC-3 network was prepared using a simple, environmentally friendly magnetic stirring process, wherein Cu groups were intercalated into the hydroxylated TAC active sites to enhance the electrochemical properties. The physicochemical properties of Cu-TAC-3 were characterized spectroscopically. Furthermore, a Cu-TAC-3-modified glassy carbon electrode (GCE) was fabricated that could electrochemically detect FLU under various conditions, achieving a good sensitivity of 0.7033 μA/µM cm−2, linearity between 0.001 to83.76 μM, and a low limit of detection of 0.54 nM (70 ng mL−1). Cu-TAC-3/GCE demonstrated excellent electrochemical activity toward FLU even in real environmental samples, with a recovery of above 97 % from spiked samples. These sensors are therefore practical for the on-site electrochemical monitoring of FLU.