Fluorescence polarization immunoassays for carbamazepine – comparison of tracers and formats

摘要

For the antiepileptic drug and anthropogenic marker carbamazepine (CBZ), a fast and cost-effective immunoassay based on fluorescence polarization (FPIA) was developed. The required fluorophore conjugates were synthesized from different fluorescein and CBZ derivatives. The most suitable tracer was CBZa€“triglycinea€“5-(aminoacetamido)fluorescein. Additionally, the applicability of the assay in tubes and on microtiter plates was tested. The first format can be performed in a portable instrument and therefore can be applied in field measurements. The measurement of an individual sample can be carried out within 4 min. This assay shows a measurement range of 2.5a€“1000 ??g La?’1 and a test midpoint (or IC50) of 36 ??g La?’1. The FPIA performed on microtiter plates is useful for the assay development and is suitable for a very high throughput (up to 24 samples in 20 min). The test midpoint of this assay is 13 ??g La?’1 and the measurement range is 1.5a€“300 ??g La?’1. Furthermore, this assay requires smaller sample volumes and less reagents, including the crucial amount of antibody. The applicability of both assays to spiked surface water samples was evaluated. The recovery rates vary between 66a€“110% on microtiter plates and 81a€“140% in tubes.