Bio-Inspired Molecularly Imprinted Polymer Electrochemical Sensor for Cortisol Detection Based on O-Phenylenediamine Optimization.

This paper presents a comprehensive investigation of the various parameters involved in the fabrication of a molecularly imprinted polymer (MIP) sensor for the detection of cortisol. Parameters such as monomer concentration, electropolymerization cycles, pH, monomer-template ratio, template removal technique, and rebinding time were optimized to establish a more consistent and effective method for the fabrication of MIP sensors. Under the optimized conditions, the MIP sensor demonstrated a proportional decrease in differential pulse voltammetry peak currents with increasing cortisol concentration in the range of 0.1 to 100 nM. The sensor exhibited excellent sensitivity, with a limit of detection of 0.036 nM. Selectivity experiments using a non-imprinted polymer sensor confirmed the specific binding affinity of the MIP sensor for cortisol, distinguishing it from other steroid hormones. This study provides crucial insights into the development of a reliable and sensitive strategy for cortisol detection using O-PD-based MIPs. These findings laid the foundation for further advancements in MIP research.

Preparation and Performance Validation of Nano-Perovskite Type for Carbon Dioxide Reforming of Methane.

This paper describes the La0.8Sr0.2NiO3 perovskite-type catalysts supported on α-Al2O3 that were prepared by polyol method and used as a catalyst for the carbon dioxide reforming of methane. The effect of the molar concentration of polyvinyl-pyrrolidone (PVP) on the reducibility, structural properties and carbon deposition was characterized by XRD, and TGA. The carbon dioxide reforming of methane on the catalyst was performed at the different concentration of PVP. At the 1 M PVP, main characteristic peaks of perovskite structure were established without impurities, thus showing the highest catalytic activity; 87.7% and 92.1% in CH4 and CO2 conversion, respectively. After the reaction, carbon deposition was 0.4-0.6%, while 6.2% on the existing Ni catalyst, indicating the perovskite-type catalyst has a superior characteristic preventing it from the carbon deposition at the carbon dioxide reforming of methane.

Preparation and Characterization of Ni Nanostructures Coated on the Substrates for Glycerol Steam Reforming.

Glycerol is produced as a major byproduct in a biodiesel production process but it has been thrown out as a waste. The glycerol byproduct will increase rapidly in amount if the biodiesel commercialization is attainable, so a reforming technology is required for glycerol to be used as a high value product. In the present study, the catalytic activity of several supported catalysts for glycerol-steam reforming was measured. The glycerol conversion of Ni foam-supported catalyst was higher than that of other supported catalysts such as Al2O3, monolith, and SBA-15. The Ni foam-supported catalyst had a good thermal dispersion over the catalyst surface because it has higher thermal conductivity than other supported catalysts. However, hydrogen selectivity of all support catalysts showed the similar result except for SBA-15 supported catalyst on which C2H4 and C2H6 were produced.

Direct Conversion of Methane Over Oxide-Type Catalysts Supported on Mesoporous Silica Under Electric Discharge.

Direct conversion of methane over oxide-type catalysts supported on mesoporous material under the dielectric barrier discharge plasma was investigated in the present study. The oxide catalysts (MgO and NiO) supported on SBA-15 was prepared by a hydrothermal and wet-impregnation method. The low-angle XRD patterns and TEM indicate that the ordered mesoporous structure was well maintained during the catalyst preparation and reaction processes. We also conducted direct conversion of methane using the catalysts under the plasma. As a result, the specific surface area of bare SBA-15 was much higher than that of the NiO/SBA-15, followed by MgO/SBA-15. Overall, the CH4 conversion increased with increasing the specific surface area. And C2 selectivity decreased with increasing the specific surface area.

Electroless Plated Co-Ni-P-B/Ni Foam Catalyst for Hydrogen Generation from Sodium Borohydride.

Co-Ni-P-B catalyst supported on Ni foam was prepared using electroless plating for hydrogen generation from an alkaline NaBH4 solution. Co-B, Co-P-B, and Co-Ni-B were prepared for comparison. Surface morphology of catalyst/Ni foams were observed using SEM analysis. The Co- Ni-P-B/Ni foam catalyst showed the superior performance on hydrogen generation rate due to the uniform formation of catalyst particles on the surface of Ni foam. Characteristics of hydrogen generation rate on the Co-N-P-B/Ni foam catalyst were investigated at the variety of NaBH4 and NaOH concentrations. The hydrogen generation rate increased with decreasing NaBH4 concentration, while increasing NaOH concentration. Durability test was performed, resulting in the stable hydrogen generation for 6 hours.

Modified Nano-Perovskite Catalysts for the Steam and CO2 Reforming of Methane.

This paper describes the synthesis and characterization of La0.8Sr0.2NiO3 nano-perovskite type catalyst for steam-CO2 reforming (SCR) and CO2 reforming (DR) of methane. Effect of gelation agents such as PVA, EDTA and PAA on nano-perovskite structures was investigated. XRD, H2-TPR and FT-IR analysis were used to characterize the prepared catalysts. The catalytic reaction was performed in a fixed bed reactor system at 1 atm and 800 °C. The feed ratio of CH4:H2O:CO2 as reactants was adjusted according to the SCR and DR reactions. As a result, CH4 and CO2 conversions of PVA agent catalyst were higher than that of PAA and EDTA agent catalyst for DR reaction because the PVA agent catalyst had a well-established perovskite, a high absorption, a high reducibility. However, the PAA agent catalyst had a higher reactivity due to its high interaction of catalysts for SCR of methane due to its strong interaction of catalysts.