Electrochemical Determination of Famotidine in Real Samples Using rGO/Cu2O Nanocomposite Modified Carbon Paste Electrode

Here, we developed a sensitive electrochemical sensor for famotidine (FAT) using Cu2O nanoparticles and reduced graphene oxide (rGO) as a sensing platform. The Cu2O nanoparticles and rGO were synthesized through a simple process and characterized by versatile analytical methods. The prepared Cu2O nanoparticles and rGO were taken to modify the carbon paste electrode (Cu2O/rGO/CPE) and developed for the electrochemical analysis of the FAT at pH 6.0. Cu2O/rGO/CPE showed superior electrocatalytic activity for detecting FAT, attributed to the high surface area of rGO and the electrocatalytic properties of Cu2O nanoparticles. The designed FAT sensor exhibited two linear ranges from 0.1-3 µM and 3-50 µM with a detection limit of 0.08 µM (S/N=3) using a differential pulse voltammetry. The proposed sensor also showed a repeatable and stable response over one month with negligible interference from usual organic and inorganic species. The sensor was also validated measuring FAT in real samples (urine, serum and pharmaceutical tablet) with good recovery values from 99.6 to 110.9%.

An inner-filter-effect based ratiometric fluorescent sensor for the detection of uranyl ions in real samples

In this work, a ratiometric fluorescence system was designed for detection of trace UO22+ in water based on inner filter effect (IFE) between gold nanoparticles (AuNPs) and gold nanoclusters (AuNCs)....

Ultrasensitive Detection of Vitamin E by Signal Conversion Combined with Core-satellite Structure-based Plasmon Coupling Effect

Rapidly and sensitively surface-enhanced Raman scattering (SERS) detection of molecular biomarkers from real samples is still a challenge, because the intrinsically trace analytes may have a low molecular affinity for...

Histamine Detection in Mackerel (Scomberomorus Sp.) and its Products Derivatized with 9-Flourenilmethylchloroformate

Histamine is commonly present in food containing proteins, like in mackerel. Consuming fish is imperative for the improvement of human muscles. Nevertheless, some studies reported ingesting fish containing histamine more than 50 mg·kg-1 can cause toxicity. This study analyzed and determined the composition of histamine in mackerel and its products commonly consumed in Malaysia, especially on the East Coast of Malaysia. These included processed mackerel such as canned products, satay (skewed fish) and keropok lekor (fish cake/ cracker). Histamine analysis was performed using High Performance Liquid Chromatography (HPLC) equipped with a fluorescence detector. A derivatizing reaction was applied to increase the sensitivity of HPLC to histamine using 9-flourenilmethylchloroformate (FMOC-Cl). The chromatographic separation was achieved in 15 min. Method validation was in accordance to Commission Decision 657/2002/CE. The linear range was at 0.16 – 5.00 µg·mL-1 (histamine) with the LOD at 0.10 µg·mL-1 and LOQ at 0.30 µg·mL-1 . Method applicability was checked on seven real samples involving raw, cooked, and dry products, yielding acceptable recovery.

Enhanced desalination efficiency of flow-through capacitive deionization cell by mesh electrode with granular aerogel carbon in the removal of ions from synthetic and real samples

Flow-through capacitive deionization (FTCDI) is a traditional improved flow-by CDI cellular structure, used to remove ions from aqueous solutions. In this study, a new FTCDI was designed consisting of mesh electrodes (ME) containing ion-exchange membranes (IEM) and aerogel carbon granules with a specific surface area of 489 m2/g. All analyses and experiments performed showed that the new design can remove nitrate, phosphate, sodium, calcium, and chloride. Under optimal conditions, the new FTCDI system can remove 82.5, 49, 85, and 90% of sodium chloride, calcium chloride, nitrate, and phosphate with a maximum input concentration of 450 mg/L, 450 mg/L, 70 mg/L, and 3 mg/L, respectively. The efficiency of this system was also evaluated for real samples. Findings of the study showed that if the initial amount of turbidity is 12 NTU, total soluble solids (TDS) 1,700 mg/L, total hardness 540 mg/L, phosphate 0.09 mg/L, nitrate 28.8 mg/L, and electrical conductivity (EC) 3,480 μs/cm, the system can remove 25, 23.5, 33.3, 66.6, 54.4, and 39.1%, respectively.