Electrochemical Nanomolar Determination of the Anticancer Drug 5-Fluorouracil Using Chitosan Curcumin Schiff Base-Decorated NiO Nanorods Synthesized with Green Method

5-Fluorouracil (5-FU) is widely used in the treatment of various cancers, necessitating accurate and sensitive detection techniques. Hybrid materials, combining organic and inorganic components, offer superior electrochemical characteristics, including enhanced conductivity and stability. Herein, NiO nanorods (NiONRs) were synthesized using Mangifera indica leaves extract and decorated with chitosan curcumin analog Schiff base (Cs-Cur-A). The characterization of the NiONRs and Cs-Cur-A were investigated through different techniques including FT-IR, ¹HNMR, XRD, SEM, and EDX. A sensitive and selective electrochemical sensor to determine 5-FU was elucidated using a Cs-Cur-A/NiONRs modified glassy carbon electrode (GCE). The anodic peak current of 5-FU was greatly enhanced at the Cs-Cur-A/NiONRs/GCE with pH 7.0 and a scan rate of 50 mV s⁻¹. According to chronoamperometric measurements, the value of diffusion coefficient (D) was estimated to be 2.96 × 10⁻⁶ cm² s⁻¹. Using differential pulse voltammetry (DPV), the fabricated sensor exhibits a wide linear range (0.1–150.0 μM) with a low limit of detection (21.75 nM). Moreover, the proposed sensor was successfully applied to the detection of 5-FU in blood serum and urine samples with high reproducibility, repeatability, and selectivity.