RESUMO
In this study, a bimetallic palladium-copper aerogel was synthesized and used for modification of a graphite paste electrode (Pd-Cu/GPE), allowing the sensitive determination of bisphenol A (BPA). Different techniques, such as SEM, TEM, XPS, and AFM, were used for characterization of the Pd-Cu aerogel. To elucidate the properties of the Pd-Cu/GPE, the electrochemistry methods such as differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy were used. DPV measurements were conducted in phosphate electrolyte and buffer solution (0.2 M PBS, pH 5) at a potential range from 0.4 to 0.9 V vs. Ag/AgCl. The DPVs peaks currents increased linearly with BPA concentrations in the 0.04-85 and 85-305 µM ranges, with a limit of detection of 20 nM. The modified electrode was successfully used in real samples to determine BPA, and the results were compared to the standard HPLC method. The results showed that the Pd-Cu/GPE had good selectivity, stability, and sensitivity for BPA determination.
RESUMO
The widespread occurrence of endocrine disruptor compounds in wastewater has garnered significant attention owing to their toxicity, even at low concentrations, and their persistence in the water body. Among various analytical techniques, electrochemical sensors become popular for the environmental monitoring of water pollutants due to their low cost, rapid detection, high sensitivity, and selectivity. In this study, the mesoporous Ni (MNi) material was synthesized with an innovative method using Pluronic™ F-127 as a soft template and applied as a modifier for the simultaneous electrochemical sensing of hydroquinone (HQ), catechol (CC), bisphenol A (BPA), and bisphenol S (BPS). MNi with high porosity efficiently enhanced the redox-active surface area and conductivity of the glassy carbon electrode contributing to a significantly improved sensitivity in the detection of target chemicals. The pore size and surface area of MNi were estimated based on atomic force microscopy and Brunauer Emmett and Teller techniques to be â¼14.2 nm and 31.1 m2 g-1, respectively. The limit of detection for HQ, CC, BPA, and BPS was determined to be 5.3, 5.7, 5.6, and 61.5 nM, respectively. The electrochemical sensor presented in this study holds promise as a platform for developing portable and miniaturized tools offering the rapid and sensitive detection of these hazardous phenolic compounds in environmental water samples.
RESUMO
Polyserotonin-based nanoparticles are a new class of bioinspired nanomaterial with recently demonstrated therapeutic potential for future clinical applications. It is therefore important to establish a robust and rapid method of synthesizing polyserotonin nanoparticles (PSeNP) in the size range ideal for in vivo utilization. Since the formation of PSeNP is base-catalyzed, here we report the influence of solution pH, in the presence of different base systems, on the kinetics of PSeNP formation and physico-chemical properties of the resulting nanoparticles. We show that the rate of formation and the size of PSeNP depend on both the nature of the base and the initial pH of the reaction. We have also improved the kinetics of particle formation by performing the synthesis at an elevated temperature (60 °C), leading to a dramatic reduction in synthesis time from days to hours. This presents a significant advance in the efficiency of PSeNP synthesis and provides a facile approach in tuning the size of nanoparticles to suit various applications. Furthermore, we show that similar to serotonin, PSeNP also exhibits free radical scavenging property. Our results demonstrate that PSeNP has the potential to become a key player in the advancement of nanotechnology-mediated antioxidative therapy.
