Dariush Saberi

A highly selective and sensitive colorimetric sensor for the determination of nabumetone (NAB) basedon the aggregation of the thiolated -cyclodextrin (T-CD) functionalized gold nanoparticles (Au-NPs)with NAB in the presence of polyvinylpyrrolidone (PVP) was developed. Thiolated -cyclodextrin bondsto the surface of Au-NPs and forms a complex with NAB. The presence of PVP changed the NAB:T-CDcomplex to the NAB:(T-CD)2:PVP ternary complex which resulted in the aggregation of the Au-NPs.As a result of this aggregation, the localized surface plasmon resonance (LSPR) band of Au-NPs around520 nm decreased and a new red shifted band at 650 nm appeared which gradually increased with anincrease in the NAB concentration. Under the optimized conditions, the calibration curve derived from theratio of absorbance intensity at 650 nm to the original wavelength of 520 nm against NAB concentrationwas linear in the concentration range of 1–120 g L?1. The limits of detection (LOD) and quantification(LOQ) were 0.2 and 0.7 g L?1, respectively. The relative standard deviation at 20 g L?1of NAB wasfound to be 3.1%. The selectivity of the method was demonstrated through the analysis of the syntheticsamples containing the major interference compound reported in the literature. Finally, the method wassuccessfully applied to the determination of NAB in pharmaceutical, urine and wastewater samples.