On-Chip Thin Film Zernike Phase Plate for In-Focus Transmission Electron Microscopy Imaging of Organic Materials

Abstract

Transmission electron microscopy (TEM) is a powerful tool for imaging nanostructures, yet its capability is limited with respect to the imaging of organic materials because of the intrinsic low contrast problem. TEM phase plates have been in development for decades, yet a reliable phase plate technique has not been available because the performance of TEM phase plates deteriorates too quickly. Such an obstacle prohibits in-focus TEM phase imaging to be routinely achievable, thus limiting the technique being used in practical applications. Here we present an on-chip thin film Zernike phase plate which can effectively release charging and allow reliable in-focus TEM images of organic materials with enhanced contrast to be routinely obtained. With this stable system, we were able to characterize many polymer solar cell specimens and consequently identified and verified the existence of an unexpected nanoparticle phase. Furthermore, we were also able to observe the fine structures of an Escherichia coli specimen, without staining, using this on-chip thin film phase plate. Our system, which can be installed on a commercial TEM, opens up exciting possibilities for TEM to characterize organic materials.

Electron Tomography: A Three‐Dimensional Analytic Tool for Hard and Soft Materials Research

“…The zero-order beam passes through the central hole, while scattered electrons are phase-shifted by − π /2, resulting in a many-fold increase in specimen contrast. [228,229] By implementing a phase-plate with cryo-EM, visualization of small proteins with molecular mass of ca.100 kDa is promising. A phase-plate was implemented in ET by Dai et al [230] to visualize a cyanophage virus as it matured inside a Synechococcus cell (Figure 14).…”

Functionalized silica nanoparticles as a carrier for Betamethasone Sodium Phosphate: Drug release study and statistical optimization of drug loading by response surface method

“…2f, TEM of drug loaded particles is not clear enough. This is as a result of the limited capability of TEM for imaging of organic materials because of the intrinsically low contrast efficiency [24]. However, it retains some hexagonal mesochannels in its domain.…”

Highly Efficient Transfer of 7TM Membrane Protein from Native Membrane to Covalently Circularized Nanodisc

“…Using the various extinction coefficients of PM at 280 nm 37 and 560 nm 35 , and cE3D1 at 280 nm, and the ratio of absorption at 560 nm to 280 nm of PMND, it was calculated that approximately 47% of nanodiscs were embedded with bR in this study. Furthermore, high resolution Zernike phase TEM 38 , 39 images of unstained PMND showed perfect disc-shaped units, with a clear differentiation between the MSP belt and the core lipid components (Figs 3B and S5 ). It is worth noting that negative staining commonly used on TEM specimens was not required while preparing our PMND TEM specimens, as the high-resolution TEM images shown in this work were acquired by using a Zernike phase plate to improve contrast.…”