Thermodynamic, FTIR, 1H-NMR, and acoustic studies of butylated hydroxyanisole and sodium dodecyl sulfate in ethanol, water rich and ethanol rich solutions

Alkaline surface treatment and time-resolved reading of mn-doped nanocrystal signal transducer for enhanced bioassay sensitivity

Recently, Mn-doped semiconductor nanocrystals (NCs) with high brightness, long lifetimes, and low-energy excitation are emerging for time-resolved luminescence biosensing/imaging. Following our previous work on Mn-doped NCs, in this work we developed poly(styrene-co-maleic anhydride) (PSMA)-encapsulated Mn-doped AgZnInS/ZnS NCs as signal transducers for immunoassay of capsular polysaccharide (CPS), a surface antigen and also a biomarker of Burkholderia pseudomallei which causes a fatal disease called melioidosis. To enhance the assay sensitivity, a surface treatment for PSMA-encapsulated NCs (NC-probes) was performed to promote the presence of carboxyl groups that help conjugate more anti-CPS antibodies to the surface of NC-probes and thus enhance bioassay signals. Meanwhile, time-resolved reading on the luminescence of NC-probes was adopted to minimize the assay background autofluorescence. Both strategies essentially enhance the assay signal-to-background ratio (or equivalently the assay sensitivity) by increasing the signal and decreasing the background, respectively. Through performing and comparing immunoassays with different NC-probes (with and without surface treatment) and different signal reading methods (time-resolved reading and non-time-resolved reading), it was proven that the immunoassay adopting surface-treated NC-probes and time-resolved reading achieved a lower limit-of-detection (LOD) than the ones adopting non-surface-treated NC-probes or non-time-resolved reading. Moreover, the achieved LOD is comparable to the LOD of immunoassay using enzyme horseradish peroxidase as a signal transducer.

Effects of pollutants in alkali/surfactant/polymer (ASP) flooding oilfield wastewater on membrane fouling in direct contact membrane distillation by response surface methodology

The characteristic pollutants in alkali/surfactant/polymer (ASP) flooding oilfield wastewater are complex [e.g., NaCl, sodium dodecyl sulfate (SDS), petroleum, and polyacrylamide (PAM)]; thus, membrane distillation (MD) applied to treat this wastewater will be fouled and wetted easily. In this study, response surface methodology (RSM) was used to analyze the effects of pollutant interactions in ASP flooding oilfield wastewater on membrane fouling. The response model showed quantitative relationships between the membrane flux and the pollutant concentrations. The analysis of variance (p-value of the model < 0.0001, p-value of lack of fit > 0.05, R² = 0.9750 and R²_adj = 0.9500) showed that the regression equation fit the empirical data well. The results also indicated that the interactions of pollutants (NaCl and SDS; petroleum and PAM) had significant influence on the flux decline in the simulated ASP flooding oilfield wastewater. The characterization of Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) revealed that the MD membrane was fouled by simulated ASP flooding oilfield wastewater to a certain degree. Moreover, the membrane flux was restored to 86.9% after hydraulic cleaning.

Flavin-Conjugated Iron Oxide Nanoparticles as Enzyme-Inspired Photocatalysts for Azo Dye Degradation

In this work, a new photocatalytic system consisting of iron oxide nanoparticles (IONPs), coated with a catechol-flavin conjugate (DAFL), is synthesized and explored for use in water remediation. In order to test the efficiency of the catalyst, the photodegradation of amaranth (AMT), an azo dye water pollutant, was performed under aerobic and anaerobic conditions, using either ethylenediaminetetraacetic acid (EDTA) or 2-(N-morpholino)ethanesulfonic acid (MES) as electron donors. Depending on the conditions, either dye photoreduction or photooxidation were observed, indicating that flavin-coated iron-oxide nanoparticles can be used as a versatile enzyme-inspired photocatalysts.

Drug–surfactant interaction: thermo-acoustic investigation of sodium dodecyl sulfate and antimicrobial drug (levofloxacin) for potential pharmaceutical application

In the present study, the impact of the potential antimicrobial drug (levofloxacin) on the micellar system of anionic surfactant (SDS) has been studied.

A novel surfactant aided micellar system of oxidation inhibitors in clotrimazole bioadhesive gel: development, characterization, in vitro and in vivo antifungal evaluation against Candida clinical isolates

Clotrimazole (CLZ) is a widely used antifungal agent with poor aqueous solubility, which requires the development of new delivery systems to improve its therapeutic activity.