Citrate-modified silver nanoparticles as a colorimetric probe for simultaneous detection of four triptan-family drugs

We report a simple and rapid colorimetric method for selective and simultaneous detection of four triptan-family drugs (rizatriptan, naratriptan, sumatriptan, and zolmitriptan) by using citrate-capped silver nanoparticles (Ag NPs) as colorimetric sensors. The absorption spectra and solution color of citrate-capped Ag NPs undergo dramatic changes on exposure to four triptan family drugs with new surface plasmon resonance (SPR) peaks appearing at 560, 548, 520 and 570 nm for rizatriptan, naratriptan, sumatriptan, and zolmitriptan and concomitant color change from yellow to orange and to brown. This is assumed to result from the aggregation of citrate-capped Ag NPs induced by four triptan-family drugs. The UV-visible absorption spectra, FT-IR, dynamic light scattering (DLS) and transmission electron microscopic techniques were used to confirm the aggregation of citrate-capped Ag NPs-induced by four triptan-family drugs. Under the optimized conditions, good linear relationships (R-2 = 0.976-0.991) were obtained in the range of 0.001-1.0 mM, with limit of detections in the range of 7.3-84.0 nM for four triptan drugs. This method was successfully applied to detect four triptan-family drugs simultaneously in pharmaceutical samples (tablets and nasal spray) with minimized sample volumes. (C) 2014 Elsevier B.V. All rights reserved.