A robust molecular probe for Ångstrom-scale analytics in liquids

Abstract

Traditionally, nanomaterial profiling using a single-molecule-terminated scanning probe is performed at the vacuum–solid interface often at a few Kelvin, but is not a notion immediately associated with liquid–solid interface at room temperature. Here, using a scanning tunnelling probe functionalized with a single C60 molecule stabilized in a high-density liquid, we resolve low-dimensional surface defects, atomic interfaces and capture Ångstrom-level bond-length variations in single-layer graphene and MoS2. Atom-by-atom controllable imaging contrast is demonstrated at room temperature and the electronic structure of the C60–metal probe complex within the encompassing liquid molecules is clarified using density functional theory. Our findings demonstrates that operating a robust single-molecular probe is not restricted to ultra-high vacuum and cryogenic settings. Hence the scope of high-precision analytics can be extended towards resolving sub-molecular features of organic elements and gauging ambient compatibility of emerging layered materials with atomic-scale sensitivity under experimentally less stringent conditions.

In Situ Observation of Chemically Induced Protein Denaturation at Solvated Interfaces

“…Hence, a clear result from the AFM measurements was the formation of ferritin nanorings, together with smaller subunits and a small population of natively folded ferritin proteins. Figure d is a 3-D rendered AFM topograph of a well-resolved ferritin ring adsorbed at the edge of an out-of-plane wrinkle (indicated by the blue arrow in Figure d) typically observed on graphene surfaces. , Closer inspection of the 3D-projected ferritin ring in Figure d reveals the differences in height along the rim and confirms that the ferritin ring itself is hollow in the center. A large-area AFM image in the inset of Figure d shows the occurrence of other ring-like structures in the vicinity of the ferritin ring and the presence of smaller-sized ferritin subunits.…”

Polymer–Nanocarbon Topological and Electronic Interface

“…To experimentally verify the assembly and electronic interaction between the polymeric strands on the SWCNTs we conducted high-resolution STM and STS measurements (see schematic representation of the experimental setup in Figure a) along the length of the hybrid complex. Previously, we have employed this tool for atomic-scale registry of surface-confined soft nanomaterials in a liquid environment. − Typically, before commencing imaging and spectroscopic analysis of single PW-SWCNTs, the STM tip quality is verified by means of controls where the atomic lattice and bandstructure of the underlying graphene surface is resolved (see Figure S1, Supporting Information) in toluene environment. A spatially magnified constant-current STM image of a single PW-SWCNT (tube diameter: ∼1.5 nm) is shown in the inset of Figure b.…”

“…Conversely, in our experiments, the liquid-phase solubilized PW-SWCNTs were deposited onto graphene grown on Cu foil, wherein the single-layer graphene should serve as a spacer to electronically decouple the overlying carbon nanotube. However, it has been shown that the atomic lattice of graphene has topological imperfections such as point-defects , through which electrons could still tunnel through from the underlying Cu . This result suggests that a tightly packed polymeric assembly on the carbon backbone tends to reduce the nanotube–metal electronic overlap.…”

Wafer‐Scale Synthesis of Reliable High‐Mobility Molybdenum Disulfide Thin Films via Inhibitor‐Utilizing Atomic Layer Deposition

“…Note that, in this study, we could employ the AFM analysis to measure the grain size in an MoS 2 film of a few layers thick. due to a height difference at the uppermost MoS 2 film layer, which is now growing and cannot form a full coverage yet . Further details are described in Supporting Information (see Figure S4 and the “Characterization of Grain Size in cALD and iALD MoS 2 using AFM” section in Supporting Information).…”