title: A sensitive voltammetric sensor for detecting betamethasone in biological fluids.
abstract: A rapid and sensitive voltammetric sensor based on reduction of betamethasone has been developed using single wall carbon nanotube modified edge plane pyrolytic graphite electrode (SWNT/EPPGE). The reduction of betamethasone occurred in a well-defined, pH dependent peak. Linear calibration curve was obtained in the range 1 to 25 nM in 1.0 M phosphate buffer solution (PBS) of pH 7.2 with the limit of detection (3sigma / slope) as 0.50 nM. The analytical utility of the developed method has been demonstarted by sensing the drug in human body fluids and for the determination of betamethasone content in several commercially available pharmaceutical preparations. Interfering effect of some common metabolites including ascorbic acid, uric acid, albumin and hypoxanthine has also been evaluated. A comparison of the observed results of proposed method with HPLC clearly indicates that the results of both methods are essentially similar.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Roorkee, India. rngcyfcy@iitr.ernet.in
authors.forename: Rajendra N
authors.initials: RN
authors.lastname: Goyal
authors.forename: Sunita
authors.initials: S
authors.lastname: Bishnoi
authors.forename: Anoop Raj S
authors.initials: AR
authors.lastname: Rana
mesh_terms: D000328:Adult; D000418:Albumins / Q000032:analysis / Q000378:metabolism; D001205:Ascorbic Acid / Q000032:analysis / Q000378:metabolism; D001623:Betamethasone / Q000032:analysis*; D001826:Body Fluids / Q000737:chemistry* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry; D004566:Electrodes; D005260:Female; D006108:Graphite / Q000737:chemistry; D057166:High-Throughput Screening Assays / Q000379:methods; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019271:Hypoxanthine / Q000032:analysis / Q000378:metabolism; D008297:Male; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry; D010316:Particle Size; D012680:Sensitivity and Specificity; D013499:Surface Properties; D014527:Uric Acid / Q000032:analysis / Q000378:metabolism
chemical_list: D000418:Albumins; D037742:Nanotubes, Carbon; D014527:Uric Acid; D019271:Hypoxanthine; D006108:Graphite; D001623:Betamethasone; D001205:Ascorbic Acid