Cyclodextrin-mediated gold nanoparticles as multisensing probe for the selective detection of hydroxychloroquine drug.

β-Cyclodextrin (β-CD) modified gold nanoparticles (AuNP) were rapidly synthesized using microwave assisted procedure. Parameters, such as time, pH and concentrations of β-CD and gold, were optimized for the synthesis of β-CD-AuNP. The addition of enantiomers and racemic mixture of hydroxychloroquine (R-HCQ, S-HCQ and RS-HCQ) drugs and their interaction with β-CD led to a red shift in the surface plasmon resonance of β-CD-AuNP. The changes associated with the introduction of HCQ in β-CD-AuNP were studied using various characterization techniques such as UV-vis, FT-IR, XRD, dynamic light scattering, zeta potential, transmission electron microscopy, fluorescence spectroscopy and electrochemical techniques. The host-guest interaction of β-cyclodextrin with S-HCQ, R-HCQ and RS-HCQ resulted in the aggregation of gold nanoparticles. The surface plasmon resonance at 521 nm for β-CD-AuNP was shifted to 600, 620 and 670 nm on the addition of S-HCQ, R-HCQ and RS-HCQ, respectively, with a color change from pink to blue. The selectivity and sensitivity of the developed system for RS-HCQ were investigated and the limit of detection (LOD=3 s/m) was found to be 2.61, 0.15, and 0.85 nM for optical, fluorescence and electrochemical methods, respectively. The successful monitoring of RS-HCQ drug in pharmaceutical samples is possible with these techniques. ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available for this article at 10.1007/s11814-020-0719-7 and is accessible for authorized users. © The Korean Institute of Chemical Engineers 2021.