Abstract

Background: Recently, the use of functionalized metal nanoparticles as colorimetric probes for the detection of a variety of compounds including drugs and pesticide have received considerable attention. Highly sensitive, selective, and cost effective method without any pretreatment of analyte for pharmaceutical analysis is of immense research interest to (bio)analytical / pharmaceutical chemist.

Objective: Gold and silver nanoparticles having good optical properties are responsible for spectral change between dispersed and aggregated states of nanoparticles (NPs). In this context, 2,4- dinitrophenylhydrazine dithiocarbamate modified silver nanoparticles which serves as a chemical sensor for the colorimetric detection of omeprazole; is the main objective of this current study.

Method: The ligand functionalised silver nanoparticles were synthesized, and characterized with confirmation by UV-Vis, proton NMR, FT-IR spectroscopy and AFM technique. It was found that these conjugates are stable upto 48 hours at room temperature. A UV-visible spectroscopy of reaction mixture with omeprazole at optimized pH 8 revealed reduction in the surface plasmon resonance (SPR) Spectroscopy.

Results: Peak of Surface Plasmon Resonance (SPR) of 2,4-dinitrophenylhydrazine dithiocarbamate modified silver nanoparticles were appeared around 400 nm. A new peak appeared at 520 nm with a distinct colour change from yellow to orange. Under optimized conditions the linear range was found to be 0.005-0.3 mM, and the detection limit is 5x10-6M.

Conclusion: This newly developed method reported here could successively be applied for the determination of omeprazole in pharmaceutical samples with no interference from the matrixes.

Keywords: 2, 4-Dinitrophenylhydrazine dithiocarbamate, AFM technique, colorimetric determination, functionalised silver nanoparticles, omeprazole, pharmaceutical, sensors.

Graphical Abstract