Synthesis of hyperbranched polymer films via electrodeposition and oxygen-tolerant surface-initiated photoinduced polymerization

A novel extraction method for three ochratoxins in human urine based on polystyrene/polyethersulfone electrospun nanofibers coated with copper nanoparticles

In this study, four types of nanofibers were prepared via electrospinning and characterized through SEM, TEM, EDS, FTIR, TG, XPS and water contact angle analyses, and the novel polystyrene/polyethersulfone nanofibers coated with copper nanoparticles (PS/PES-CuNPs nanofibers) were developed as an ideal adsorbent for the extraction of three ochratoxins from human urine. The solid-phase extractant of sample pretreatment displayed preferable sensitivity and an extraction effect, and the analytical method based on the novel packed-fiber solid-phase extraction strategy followed by high performance liquid chromatography-fluorescence detection (PFSPE-HPLC-FLD) achieved an exceedingly low limit of detection (LOD) and limit of quantification (LOQ) of 0.108-0.162 μg L-1 and 0.658-0.701 μg L-1, respectively; a high spiked recovery of 71.3-92.0% and a lower adsorption time of 7 min, thus demonstrating excellent results compared with other reported adsorbents for ochratoxins from various samples. With the application of this method for the detection of ochratoxins in human urine samples, six in thirty samples were tested positive. This study confirmed that the PS/PES-CuNP nanofibers and PFSPE showed promising potential as a sensitive method for simultaneous extraction and detection of ochratoxins in complex samples.

Using RAFT Polymerization Methodologies to Create Branched and Nanogel-Type Copolymers

This review aims to highlight the most recent advances in the field of the synthesis of branched copolymers and nanogels using reversible addition-fragmentation chain transfer (RAFT) polymerization. RAFT polymerization is a reversible deactivation radical polymerization technique (RDRP) that has gained tremendous attention due to its versatility, compatibility with a plethora of functional monomers, and mild polymerization conditions. These parameters lead to final polymers with good control over the molar mass and narrow molar mass distributions. Branched polymers can be defined as the incorporation of secondary polymer chains to a primary backbone, resulting in a wide range of complex macromolecular architectures, like star-shaped, graft, and hyperbranched polymers and nanogels. These subcategories will be discussed in detail in this review in terms of synthesis routes and properties, mainly in solutions.

3D Temperature-Controlled Interchangeable Pattern for Size-Selective Nanoparticle Capture

Patterned surfaces with distinct regularity and structured arrangements have attracted great interest due to their extensive promising applications. Although colloidal patterning has conventionally been used to create such surfaces, herein, we introduce a novel 3D patterned poly(N-isopropylacrylamide) (PNIPAM) surface, synthesized by using a combination of colloidal templating and surface-initiated photoinduced electron transfer-reversible addition-fragmentation chain transfer (SI-PET-RAFT) polymerization. In order to investigate the temperature-driven 3D morphological variations at a lower critical solution temperature (LCST) of ∼32 °C, multifaceted characterization techniques were employed. Atomic force microscopy confirmed the morphological transformations at 20 and 40 °C, while water contact angle measurements, upon heating, revealed distinct trends, offering insights into the correlation between surface wettability and topography adaptations. Moreover, quartz crystal microbalance with dissipation monitoring and electrochemical measurements were employed to detect the topographical adjustments of the unique hollow capsule structure within the LCST. Tests using different sizes of PSNPs shed light on the size-selective capture-release potential of the patterned PNIPAM, accentuating its biomimetic open-close behavior. Notably, our approach negates the necessity for expensive proteins, harnessing temperature adjustments to facilitate the noninvasive and efficient reversible capture and release of nanostructures. This advancement hopes to pave the way for future innovative cellular analysis platforms.