Electron microscopy contrast imaging

Transmission electron microscopy (TEM) images showed that GNPs conjugated with Tat peptide (nuclear localization sequence) were mainly located in the nucleus of fibroblast and also revealed no appreciable cytotoxic effects [22]. In contrast, Tkachenko et al. functionalized GNPs with four different nuclear localization peptides ending with a Cys residue (which contains a free thiol) to evaluate the cellular trajectories of peptide gold complexes. Functionalized GNPs were... 

In conventional electron microscopy the imaged electrons are generated by reflection, diffraction or transmission of the primary electrons directed from an external source towards the specimen. In contrast, photoemission electron microscopy employs an external photon source to generate electrons internally by... 

In contrast to many other surface analytical techniques, like e. g. scanning electron microscopy, AFM does not require vacuum. Therefore, it can be operated under ambient conditions which enables direct observation of processes at solid-gas and solid-liquid interfaces. The latter can be accomplished by means of a liquid cell which is schematically shown in Fig. 5.6. The cell is formed by the sample at the bottom, a glass cover - holding the cantilever - at the top, and a silicone o-ring seal between. Studies with such a liquid cell can also be performed under potential control which opens up valuable opportunities for electrochemistry [5.11, 5.12]. Moreover, imaging under liquids opens up the possibility to protect sensitive surfaces by in-situ preparation and imaging under an inert fluid [5.13]. 

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