▎ 摘　　要

An economical graphene-carbon paste electrode (GR/CPE) in situ modified with surfactants was used for improvement the sensitivity and selectivity of the electrochemical measurement of itraconazole drug. Among the surfactants, cationic (cetyltrimethyl ammonium bromide, CTAB) and non-ionic (Triton X-100) displayed a decrease in peak current intensity, while anionic (sodium dodecyl sulfate, SDS) exhibited better change in the electrical properties of the electrode-solution interface. The adsorbed-SDS at GR/CPE interacts with itraconazole molecules through hydrophobic and electrostatic attraction which encourages the electron transmission between the drug and electrode surface. Compared with CPE and GR/CPE, SDS-GR/CPE exhibits the enhanced peak current intensity and reduces the over potential toward itraconazole oxidation as a result of the combined effect of GR and SDS. %composition of GR/CPE and SDS concentration were optimized. Wide linear dependence of the current on bulk itraconazole concentration (1.5 x 10(-9)-7.0 x 10(-7)M) was achieved in Britton-Robinson buffer, pH 2.0 containing 0.5 mM SDS at 0.3%(w/w) GR/CPE. SDS-GR/CPE presents adequately LOD value (1.36 x 10(-9)1.07 x 10(-10)M) for the determination of itraconazole in human plasma. SDS-GR/CPE avoids interference from important common substances in biological and pharmaceutical samples. The fabricated sensor has desirable stability and reproducibility that can be used in routine quality control and pharmacokinetic studies.