Multiparametric Profiling of Single Nanoscale Extracellular Vesicles by Combined Atomic Force and Fluorescence Microscopy: Correlation and Heterogeneity in Their Molecular and Biophysical Features.

Being a key player in intercellular communications, nanoscale extracellular vesicles (EVs) offer unique opportunities for both diagnostics and therapeutics. However, their cellular origin and functional identity remain elusive due to the high heterogeneity in their molecular and physical features. Here, for the first time, multiple EV parameters involving membrane protein composition, size and mechanical properties on single small EVs (sEVs) are simultaneously studied by combined fluorescence and atomic force microscopy.

Wafer-scale fabrication of isolated luminescent silicon quantum dots using standard CMOS technology.

A wafer-scale fabrication method for isolated silicon quantum dots (Si QDs) using standard CMOS technology is presented. Reactive ion etching was performed on the device layer of a silicon-on-insulator wafer, creating nano-sized silicon islands. Subsequently, the wafer was annealed at 1100 °C for 1 h in an atmosphere of 5% H in Ar, forming a thin oxide passivating layer due to trace amounts of oxygen.

Tight-binding calculations of the optical properties of Si nanocrystals in a SiO matrix.

We develop an empirical tight binding approach for the modeling of the electronic states and optical properties of Si nanocrystals embedded in a SiO2 matrix. To simulate the wide band gap SiO2 matrix we use the virtual crystal approximation. The tight-binding parameters of the material with the diamond crystal lattice are fitted to the band structure of β-cristobalite.

Size-Dependent Phase Transition in Perovskite Nanocrystals.

The complex structure of halide and oxide perovskites strongly affects their physical properties. Here, the effect of dimensions reduced to the nanoscale has been investigated by a combination of single-dot optical experiments with a phase transition theory. Methylammonium lead bromide (CHNHPbBr) nanocrystals with two average particle sizes of ∼2 and ∼4 nm with blue and green photoluminescence, respectively, were spectrally and temporally probed on a single-particle level from 5 to 295 K.

Strong Absorption Enhancement in Si Nanorods.

We report two orders of magnitude stronger absorption in silicon nanorods relative to bulk in a wide energy range. The local field enhancement and dipole matrix element contributions were disentangled experimentally by single-dot absorption measurements on differently shaped particles as a function of excitation polarization and photon energy. Both factors substantially contribute to the observed effect as supported by simulations of the light-matter interaction and atomistic calculations of the transition matrix elements.