A novel colorimetric sensor for sensitive determination of R-citalopram based on the plasmonic properties of silver nanoparticles

Abstract

A simple and reliable colorimetric method for visual differentiation between the S-citalopram and R-citalopram enantiomers in aqueous solution based on the inherent chirality of silver nanoparticles as a colorimetric probe was presented. Upon addition of (RS)-citalopram to a solution of silver nanoparticles, a color change from yellow to red can be seen and quantified by spectrophotometry, while no color change is found upon addition of S-CIT. Citalopram enantiomers were determined over a concentration range of 7.6 × 10⁻⁹ to 1.7 × 10⁻⁴ M with a detection limit of 3.0 × 10⁻⁹ M. The developed method showed good repeatability and linearity, as well as advantages such as low cost, simplicity, sensitivity, and high feasibility. More importantly silver nanoparticles selectively interacted with R-CIT from a solution of (RS)-CIT.