Palladium nanoclusters enhanced rhodamine B-K3Fe(CN)6 chemiluminescence system and its application for the sensitive determination of phenobarbital

Development of a new sensitive assay for the determination of drugs is of great importance in analytical chemistry. Herein, a reliable chemiluminescence (CL) probe was developed for the sensitive determination of phenobarbital. The method was based on the enhancement effect of palladium nanoclusters (Pd NCs) on the weak CL emission of K3Fe(CN)6 -rhodamine B reaction in alkaline media [1-3]. Pd NCs were prepared by facile procedure and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR). The oxidation reaction alkaline rhodamine B by K3Fe(CN)6 could generate a very weak CL emission, but in the presence of Pd NCs, a remarkable intensified CL emission was obtained. This effect was ascribed to the catalytic activity of Pd NCs. Besides, it is observed that the addition of phenobarbital in the reaction media caused a remarkable quenching effect on the obtained CL emission. This effect was formed the basis of a sensitive sensor for the detection of phenobarbital. Under the optimized conditions, the proposed CL system exhibited a linear relationship between the CL intensity and phenobarbital concentration in the range of 0.02-300 µg mL−1, with a detection limit (3Sb/m) of 5 ng mL−1. Also, the relative standard deviation (RSD) was found to be 3.4% for repetitive determinations of 50 µg mL−1 phenobarbital (n=10).