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Summary Here, we elucidate the mechanism for Al2O3 atomic layer deposition (ALD) on LiMn2O4 (LMO) cathodes for lithium-ion batteries by using in situ and ex situ experimental characterization coupled with density functional theory (DFT) calculations. We demonstrate that not only does Al2O3 coat the LMO, but the Al heteroatom of the trimethylaluminum (TMA) precursor also dopes to interstitial sites on the LMO surface, thereby reducing the oxidation state of near-surface Mn ions. DFT calculations further suggest facile transfer of methyl groups from the TMA precursor to oxygen atoms on the LMO surface, which blocks adsorption sites for subsequent TMA adsorption. These predictions are supported by quartz crystal microbalance experiments demonstrating inhibited growth below ten ALD Al2O3 cycles, suggesting that sub-monolayer coverages of alumina are present on the LMO surface in the early stages of film growth. In comparison with fully conformal films, these sub-monolayer coatings show enhanced electrochemical capacity when cycled in coin cells.

Real-time label-free electrical detection of proteins, including cardiac troponin (cTn), is demonstrated using functionalized SnO2 nanobelt field-effect transistors (FETs) with integrated microfluidics. Selective biomolecular functionalization of the active SnO2 nanobelt channel and effective passivation of the substrate surface were realized and verified through fluorescence microscopy. The validation/verification of the sensing scheme was initially demonstrated via detection of biotin–streptavidin binding: devices with single biotinylated SnO2 nanobelts showed pronounced conductance changes in response to streptavidin binding. Importantly, the pH-dependence of the conductance changes was fully consistent with the charged states of streptavidin at different pH. Moreover, the specificity of the sensors’ electrical responses was confirmed by co-labeling with quantum dots. Finally, the sensing platform was successfully applied for detection of the cardiac troponin I (cTnI) subunit within cTn, a clinically important protein marker for myocardial infarction.

High content carbon nanotubes mats have been produced to a range of thicknesses and diameters by covalent bonded cross-linking of thiolated multi-walled carbon nanotubes. The Michael addition pathway was used to cross-link benzoquinone to thiol groups attached to the surface of the nanotubes. The mats were characterized by a variety of techniques including X-ray photoelectron spectroscopy, tensile strength as well as qualitative structural analysis by scanning electron microscopy. It was found that the optimum ratio by weight for cross-linking benzoquinone to thiolated carbon nanotubes was ca. 5:1. This work provided a simple route to the production of mats without high pressure processing or irradiation techniques generally used to produce Buckypaper which can require pressure control chambers, argon and hydrogen ion beams and high temperatures. The mat surface can be further functionalized with nanoparticles to form advanced carbon composite materials.