Fluorescent Imprinted Nanoparticles for the Effective Monitoring of Irinotecan in Human Plasma

Fluorescent, imprinted nanosized polymers for the detection of irinotecan have been synthesised using a napthalimide polymerisable derivative (2-allyl-6-[2-(aminoethyl)-amino] napthalimide) as functional monomer. The imprinted polymers contain ethylene glycol dimethacrylate (EGDMA) as a cross-linker and were prepared by high dilution radical polymerisation in dimethylsulphoxide (DMSO). The material was able to rebind irinotecan up to 18 nmol/mg with good specificity. Fluorescence emission at 525 nm (excitation at 448 nm) was quenched by increasing concentrations of irinotecan via a static mechanism and also in analytically useful environments as mixtures of human plasma and organic solvents. This allowed the direct detection of irinotecan (in the 10–30 μM range) in human plasma treated with acetonitrile; the limit of detection (LOD) was 9.4 nM, with within-run variability of 10% and day-to-day variability of 13%.