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.

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.

ContextSingle-wall carbon nanotubes (SWCNT) dispersed in water with the help of sodium dodecyl sulfate (SDS) surfactants exhibit a temperature dependent near infrared (NIR) exciton spectrum. Due to their biocompatibility and NIR spectrum falling within the transparent window for biological tissue, SWCNTs hold potential for sensing temperature inside cells. Here, we seek to elucidate the mechanism responsible for this temperature dependence, focusing on changes in the water coverage of the SWCNT as the surfactant structure changes with temperature. We compare optical absorption spectra in the UV–Vis-IR range and fully atomistic molecular dynamics (MD) simulations. The observed temperature dependence of the spectra for various SWCNTs may be attributed to changes in the dielectric environment and its impact on excitons. MD simulations reveal that the adsorbed SDS molecules effectively shield the SWCNT, with ~ 70% of water molecules removed from the first two adlayers; this coverage shows a modest temperature dependence. Although we are not able to directly demonstrate how this influences the NIR spectrum, this represents a potential pathway given the strong influence of the water environment on the excitons in SWCNTs.MethodsOptical absorption measurements were carried out in the UV–Vis-NIR range using a Varian Cary 5000 spectrophotometer in a temperature-controlled environment. PeakFit™ v. 4.06 was used as peak-fitting program in the spectral range 900–1400 nm (890–1380 meV) as a function of the temperature. Fully atomistic molecular dynamics simulations were conducted using the NAMD2 package. The CHARMM force field comprising two-body bond stretching, three-body angle deformation, four-body dihedral angle deformation, and nonbonded interactions (electrostatic and Lennard–Jones 6–16 potentials) was employed.