Exploitation of localized surface plasmon resonance of silver/gold nanoparticles for the fluorescence quantification of angiotensin II receptor antagonists in their tablets and bio-samples
The present study suggested six different fluorimetric systems for the determination of three angiotensin II receptor antagonists, candesartan cilexetil (CDC), valsartan (VAL) and telmisartan (TEL) in their bulk and pharmaceutical dosage forms. The fluorescence intensities (FIs) were recorded by measuring the high catalytic potential activity of silver or gold nanoparticles (AgNPs or AuNPs) at λex 525, 420 and 330 nm and λem 555, 490 and 400 nm for CDC, VAL and TEL, respectively. All experimental measurements were carried out under optimum conditions using the CDC–Tb(III)–AgNPs, CDC–Tb(III)–AuNPs, VAL–Eu(III)–AgNPs, VAL–Eu(III)–AuNPs, TEL–SDS–AgNPs and TEL–SDS–AuNPs systems. The fluorescence (FL) signals displayed linear concentration ranges of 0.01–300, 0.02–120 and 2.0–30 ng mL−1 for CDC, VAL and TEL in the presence of AgNPs, respectively, and 0.05–60, 0.1–80 and 0.1–250 ng mL−1 for the same drugs in the presence of AuNPs, respectively. The influence of possible coexisting species and additives was tested. ICH guidelines were followed to validate the developed methods. All suggested FL systems were successfully used to monitor the investigated drugs in bulk, tablets and bio-samples. The obtained data were compared with those of other reported methods revealing high agreement.