Selective labeling of phosphatidylserine for cryo-TEM by a two-step immunogold method.

Immunogold labeling in transmission electron microscopy (TEM) utilizes the high electron density of gold nanoparticles conjugated to proteins to identify specific antigens in biological samples. In this work we applied the concept of immunogold labeling for the labeling of negatively charged phospholipids, namely phosphatidylserine, by a simple protocol, performed entirely in the liquid-phase, from which cryo-TEM specimens can be directly prepared. Labeling included a two-step process using biotinylated annexin-V and gold-conjugated streptavidin.

Tunable touch sensor and combined sensing platform: toward nanoparticle-based electronic skin.

In this paper, we present touch (or pressure) flexible sensors based on monolayer-capped nanoparticles (MCNPs) that are potentially inexpensive, could allow low-voltage operation, and could provide a platform for multifunctional applications. We show that modifying the mechanical and geometrical properties of the flexible substrates, on which the MCNP films are deposited, allows measuring a large span of loads ranging between tens of mg to tens of grams. All flexible sensors exhibited repeatable responses even after a large number of bending cycles.