An electrochemical sensor is described for highly sensitive and selective determination of anticancer drug irinitecan (IRT). Gold
nanoparticles anchored graphitized carbon nanofibers (Au@GCNFs) was prepared. Au@GCNFs was characterized by X-ray
diffraction, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray. The combination of
high catalytic activity of the nanocomposite Au@GCNFs and the good conductivity ionic liquid [BMIM]PF6 (IL) resulted in a
modified paste electrode (IL/Au@GCNFs-PE). The IL/Au@GCNFs-PE exhibits excellent electrocatalytic activity for selective
determination of IRT in the presence of physiological electroactive species, such as ascorbic acid (AA), dopamine (DA), uric acid
(UA), and caffeine (CAF) mixture, typically at working potential of 0.88 V vs. Ag/AgCl. The linear response ranges 4.0 nM–
1.79 μM and 4.5 nM–1.57 μM with limits of detection of 1.55 nM and 1.70 nM were calculated for IRT in the absence and
presence of the quaternary mixture, respectively. The sensor is reproducible and stable over four weeks, and interference by
biologically essential compounds is negligible. The method was applied to the determination of IRT in pharmaceutical formulations,
in spiked blood serum and urine, and in clinical patient blood. The recovery values ranged from 96.0 to 104.2%.