凯发

Scanning Probe Microscopy (SPM) is required in many fields of science, as it allows fabrication and characterization with high spatial resolution. However, the main problem associated to research with SPMs is that the ultra sharp nanoprobe tips can wear out extremely fast after some spectroscopic measurements or lateral scans, due to high currents and/or mechanical frictions. Here we present an exciting development of inexpensive and ultra-durable graphene nanoprobes by coating standard metalvarnished SPM probes with high quality solution-processed graphene sheets. Scanning Electronic Microscopy (SEM) images (Figure 1a) reveal that the graphene sheets can strongly attach to the apex of probes, leading to a conformal coating. The effect of high current densities is analyzed by means of spectroscopic current-voltage (I-V) and current-time (I-t) curves (see Figure 1b) collected with the Conductive Atomic Force Microscopy (CAFM) on a conductive substrate sample. Graphene nanoprobes showed larger lifetimes and smaller variability compared to graphene-free counterparts, indicating the enhanced durability. This kind of graphene nanoprobes encompass for the first time all wanted capabilities in a single nanoprobe: low price, ultra high durability, low tip radius and low variability, which extraordinarily increases the quality and reduces the cost of the research. Apart from this, graphene nanoprobes show interesting additional capabilities, especially the hydrophobicity (see Figures1c and 1d), which will avoid undesired chemical reactions between the sample and tip.