Development and validation of a selective SPR aptasensor for the detection of anticancer drug irinotecan in human plasma samples

In this work, a surface plasmon resonance (SPR)-based assay for the quantification of antineoplastic drug irinotecan in human plasma samples has been developed for the first time. The selective binding of irinotecan with an aptamer receptor, operating in human plasma, allowed to set-up a novel analytical methodology to detect the drug in the analytical range of interest by using SPR as detection technique. After hybridizing the aptamer to the sensing platform and optimizing the sample preparation procedure, a quantitative assay was validated according to FDA regulatory guidelines. The analytical working range was found between 100 and 7500 ng mL(-1) with negligible interferences from plasma components and co-medication associated with the administration of irinotecan. The utility of the new SPR assay was confirmed by analyzing plasma samples in parallel with LC-MS as reference technique, providing a new analytical tool for the therapeutic drug monitoring of irinotecan in patients under chemotherapy regimens.