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The measurement of pharmaceutical compounds in biological fluids is considered an effective way to evaluate their effectiveness. On the other hand, lorazepam is a drug with good efficiency in treatment and some side effects, which measurement is very important. In this study, the ZnO nanoparticle was synthesized as an electrocatalyst by chemical precipitation method. In continuous a simple modification on paste electrode (PE) by ZnO nanoparticle (ZnO-NPs) and 1-hexyl-3-methylimidazolium chloride (HMImCl) was made and new sensor was used for sensing of lorazepam. The HMImCl/ZnO-NPs/PE showed catalytic behavior on oxidation signal of lorazepam and improved its signal about 2.17 times compared to unmodified PE. On the other hand, oxidation signal of lorazepam was reduced about 110 mV at surface of HMImCl/ZnO-NPs/PE compare to unmodified PE that confirm accelerating the electron exchange process after modification of sensor by HMImCl and ZnO-NPs as powerful catalysts. The HMImCl/ZnO-NPs/PE was used for monitoring of lorazepam in water and injection samples and results showed recovery data 98.5 to 103.5 % that are acceptable for a new sensor.

An electrochemical chemical sensor for determination of uric acid (UA) with highly sensitive and widely working range was fabricated using zinc layered hydroxide-sodium dodecyl sulphate-propoxur (ZLH-SDS-PRO) nanocomposites modified with multiwall carbon nanotubes (MWCNT). Introduction of the ZLH-SDS-PRO as a conducting matrix has enhanced the conductivity of MWCNT. The ZLH-SDS-PRO/MWCNT morphology was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), meanwhile the electrochemical behaviour of UA and K3[Fe(CN)6] at ZLH-SDS-PRO/MWCNT paste electrode was studied by square wave voltammetry (SWV) and cyclic voltammetry (CV), respectively. Under the optimized experimental conditions, the electrode established linear plot for UA from 7.0 µmol/L to 0.7 mmol/L (R2 = 0.9920) and the LOD was calculated to be 4.28 µmol/L (S/N = 3). The fabricated electrochemical electrode was successfully applied to urine samples and exhibit excellent stability and reproducibility, which made it worthwhile to be explored for analytical applications.

The removal of halogenated dye and sensing of pharmaceutical products in the water bodies with quick purification time is of high need due to the scarcity of drinking water. The present work reported on the preparation of graphitic carbon nitride (g-C 3 N 4) for quick time water contaminant adsorption, followed by synthesizing silver nanoparticles decorated graphitic carbon nitride for pharmaceutical product sensing using in-situ SERS technique. The prepared graphitic carbon nitride is used to study the adsorption behavior of water contaminants at room temperature, in the presence of methylene blue (MB) as an adsorbate model. The water-soluble graphitic carbon nitride, even at low concentration, possesses an excellent ability to adsorb halogenated organic dye. As a result, the dyes are found to adsorb within ∼5s even without any additional physical or chemical activation. From the UV–Vis absorption investigations, it has been perceived that in the presence of graphitic carbon nitride (g-C 3 N 4) the dye adsorption efficacy is observed nearly 80% with the well fitted linearly of R2 = 0.9731. Effective in-situ surface-enhanced Raman scattering (SERS) studies for Ag nanoparticles decorated graphitic carbon nitride has been carried out and the obtained result shows good sensing performance of the material towards acetaminophen drug. This method opens the possibility of the Nobel metal decorated graphitic carbon nitride for real-time sensing of SERS-based drug products along with the development of high-performance sensing of the target analyte in the future. Image 1 • g-C 3 N 4 has been prepared using urea and thiourea as a precursor material. • Methylene blue was used as a water pollution adsorbate model in presence of g-C 3 N 4. • In the presence of g-C 3 N 4 , the halogenated dye adsorbed within ∼5s. • The prepared Ag@g-C 3 N 4 has been utilized for in-situ SERS pharmaceutical sensing. [ABSTRACT FROM AUTHOR]