An immunochromatographic sensor for the detection of 5-fluorouracil in human plasma

Abstract

This study prepared a colloidal gold-based immunochromatographic strip (CG-ICS) for the detection of 5-fluorouracil (5-FU) in human plasma, for therapeutic drug monitoring. Three haptens were synthesized with different carboxyl introductory positions and with different carbon chain lengths for the spacer arm, and were used to screen the coating antigens and immunogens. A highly sensitive and specific monoclonal antibody (mAb) 3C12 with an IC50 value of 4.359 ng/mL detected by ic-ELISA was produced for the construction of the strip. The visual limit of detection (vLOD) for semi-quantitative analysis of the CG-ICS was 50 ng/mL and the cut-off value was 2000 ng/mL. Furthermore, the calculated LOD (cLOD) value and linear range for quantitative detection were 1.464 ng/mL and 5.432–367.627 ng/mL, respectively. This detection required at most 10 min. In addition, the recovery rate of the spiked 5-FU in human plasma detected by the CG-ICS was 91.77 % to 94.04 %, which matched very well the results from LC-MS/MS. For real positive samples, the test results of the CG-ICS were consistent with those of LC-MS/MS. These findings suggest that the CG-ICS detection method is suitable for the rapid detection of 5-FU.