A novel potentiometric sensor based on ZnO decorated polyaniline/coal nanocomposite for diltiazem determination.

Diltiazem (DTZ) is one of the most effective medications for treating cardiovascular diseases. It has been widely used for the treatment of angina pectoris, hypertension and some types of arrhythmia. The development and application of a modified carbon paste sensor with improved detection limits for the potentiometric determination of diltiazem are the main goals of the current study. Sensitivity, long-term stability, reproducibility and improving the electrochemical performance are among the characteristics that have undergone careful examination. A modified carbon paste sensor based on ß-cyclodextrin (ß-CD) as ionophore, a lipophilic anionic additive (NaTPB) and a ZnO-decorated polyaniline/coal nanocomposite (ZnO@PANI/C) dissolved in dibutyl phthalate plasticizer, exhibited the best performance and Nernstian slope. The ZnO@PANI/C based sensor succeeded in lowering the detection limit to 5.0 × 10-7 through the linear range 1.0 × 10-6 to 1.0 × 10-2 mol L-1 with fast response time ≤ 10.0 s. The prepared nanomaterial was characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM). The surface properties of the proposed sensor were characterized by electrochemical impedance spectroscopy (EIS). The selectivity behavior of the investigated sensor was tested against a drug with similar chemical structure and biologically important blood electrolytes (Na+, K+, Mg2+, and Ca2+). The proposed analytical method was applied for DTZ analysis in pure drug, pharmaceutical products and industrial water samples with excellent recovery data.

Potentiometric sensor based on novel flowered-like Mg-Al layered double hydroxides/multiwalled carbon nanotubes nanocomposite for bambuterol hydrochloride determination.

Nowadays, development of highly efficient potentiometric sensors attracts the attention of many researchers over the world; due to the great expansion of portable analytical devices. This study aims to apply a current development to the construction and sense of carbon paste sensors based on flowered-like Mg-Al layered double hydroxides/multiwalled carbon nanotubes (FLLDH/MWCNTs) (sensor І), FLLDH/titanate nanotubes (TNTs) (sensor ІІ) and MWCNTs/TNTs (sensor ІІІ) nanocomposites for bambuterol hydrochloride analysis; to enhance the potentiometric response towards determination of the drug. The sensors exhibited excellent Nernstian slopes 58.8 ±â€¯0.5, 58.5 ±â€¯0.8 and 57.4 ±â€¯0.7 mV/decade with linear working ranges of 1.0 × 10-7-1.0 × 10-2, 1.0 × 10-6-1.0 × 10-2 and 1.0 × 10-7-1.0 × 10-2 mol L-1, detection limits 2.3 × 10-8, 2.5 × 10-7and 7.5 × 10-8 mol L-1 and quantification limits of 7.6 × 10-8, 8.3 × 10-7and 2.5 × 10-7 mol L-1 for sensor І, ІІ and ІІІ, respectively. The selectivity behaviour of the investigated sensors was tested against biologically important blood electrolytes (Na+, K+, Mg2+, Ca2+). The proposed analytical method was successfully applied for BAM determination in pure drug, pharmaceutical products, surface water, human plasma and urine samples with excellent recovery data (99.62, 99.10 and 98.95%) for the three sensors, respectively.