Understanding the techno-functional properties of underutilized plant -based proteins, such as potato proteins, is essential in the context of the development of alternative proteins and plant -based foods. In this study, the aggregation kinetics of patatin-rich dispersions at two concentrations (1% and 4% w/w) and pH levels (6 and 7) were evaluated and compared under two physical processes: heat treatment (45 C-degrees, 50 C-degrees, 55 C-degrees) and high hydrostatic pressure (400 MPa, 600 MPa). Distinct patterns in patatin aggregation were observed based on the processing and physicochemical conditions. Under all processing conditions, larger aggregates were formed at pH 6. Heat treatment led to either a slow or rapid gradual increase in aggregate size at the different pH and protein concentrations, while high -pressure -generated nanoaggregates displayed pH and pressure -level dependent kinetic behaviors. Some micro, sub -micron and nanoaggregates were then selected and characterized in terms of denaturation yield, molecular structure, and protein interactions. High-pressure treatment induced a significant reduction in protein intrinsic fluorescence intensity suggesting irreversible partial protein unfolding, irrespective of pressure or pH. The highest pressure level (600 MPa) led to significantly higher denaturation, regardless of pH. Similar trends in secondary structure modifications were observed for the different treatment conditions and were characterized by an increase in beta-sheet content and a reduction in alpha-helices. The structural changes in the high pressure -treated samples were particularly influenced by pH. This study provides a deeper understanding of potato protein behavior under different treatment conditions, which may contribute to the design of novel plant -based protein nanostructures.

Raman spectroscopy is a widely used technique to characterize nanomaterials because of its convenience, non-destructiveness, and sensitivity to materials change. The primary purpose of this work is to determine via Raman spectroscopy the average thickness of MoS 2 thin films synthesized by direct liquid injection pulsed-pressure chemical vapor deposition (DLI-PP-CVD). Such samples are constituted of nanoflakes (with a lateral size of typically 50 nm, i.e., well below the laser spot size), with possibly a distribution of thicknesses and twist angles between stacked layers. As an essential preliminary, we first reassess the applicability of different Raman criteria to determine the thicknesses (or layer number, N ) of MoS 2 flakes from measurements performed on reference samples, namely well-characterized mechanically exfoliated or standard chemical vapor deposition MoS 2 large flakes deposited on 90 ± 6 nm SiO 2 on Si substrates. Then, we discuss the applicability of the same criteria for significantly different DLI-PP-CVD MoS 2 samples with average thicknesses ranging from sub-monolayer up to three layers. Finally, an original procedure based on the measurement of the intensity of the layer breathing modes is proposed to evaluate the surface coverage for each N (i.e., the ratio between the surface covered by exactly N layers and the total surface) in DLI-PP-CVD MoS 2 samples.

Poly(N-isopropylacrylamide) (PNIPAM) is one of the most well studied thermoresponsive polymers and its microgels undergo a reversible volume phase transition (VPT) at temperatures close to that of the human body. Coupling this property with the unique optical properties of single-walled carbon nanotubes (SWCNT) in the near infrared (NIR) leads to interesting nanohybrids that could be used as multi-responsive sensors/actuators for biological applications.We show the synthesis of thermoresponsive SWCNT/PNIPAM hybrids using two different non-covalent strategies, preserving the nanotube optical properties such as fluorescence. The first strategy involves the dispersion of the SWCNT in water with sodium dodecyl sulfate (SDS), and subsequent in situ synthesis of PNIPAM microgels inside the SDS coatings around the nanotubes. The second strategy starts with modifying the nanotubes with a pyrene derivative, which in turn is used as the starting point for the in situ polymerization of the PNIPAM microgels, thus ensuring that the polymer grows around the nanotubes. In both cases, we obtain hybrids showing a phase transition at temperatures close to that of the human body, with the absorption and fluorescence spectra of the hybrids in the NIR changing in response to the changing dielectric environment. These systems could be used as actuators/sensors in biological systems.