3.8 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Probe tip | 5/5 | https://en.wikipedia.org/wiki/Probe_tip | reference | science, encyclopedia | 2026-05-05T03:14:02.559156+00:00 | kb-cron |
Imaging tip using microscopy is used to take image of tip with microscopy, except scanning probe microscopy (SPM) e.g. scanning tunnelling microscopy (STM), atomic force microscopy (AFM) are reported. Using known tip characterizer is when the shape of tip is deduced by taking an image of a sample of known measurement, which is known as tip characterizer. Blind method is where tip characterizer of either known or unknown measurement is used.
== Applications == Probes tips have a wide variety of applications in different fields of science and technology. One of the major areas where probe tips are used is for application in SPM i.e., STM and AFM. For example, carbon nanotube tips in conjunction with AFM provides an excellent tool for surface characterization in the nanometer realm. CNT tips are also used in tapping-mode Scanning Force Microscopy (SFM), which is a technique where a tip taps a surface by a cantilever driven near resonant frequency of the cantilever. The CNT probe tips fabricated using CVD technique can be used for imaging of biological macromolecules, semiconductor and chemical structure. For example, it is possible to obtain an intermittent AFM contact image of IgM macromolecules with excellent resolution using a single CNT tip. Individual CNT tips can be used for high resolution imaging of protein molecules. In another application, multiwall carbon nanotube (MWCNT) and single wall carbon nanotube (SWCNT) tips were used to image amyloid β (1-40) derived protofibrils and fibrils by tapping mode AFM. Functionalized probes can be used in Chemical Force Microscopy (CFM) to measure intermolecular forces and map chemical functionality. Functionalized SWCNT probes can be used for chemically sensitive imaging with high lateral resolution and to study binding energy in chemical and biological system. Probe tips that have been functionalized with either hydrophobic or hydrophilic molecules can be used to measure the adhesive interaction between hydrophobic-hydrophobic, hydrophobic-hydrophilic, and hydrophilic-hydrophilic molecules. From these adhesive interactions the friction image of patterned sample surface can be found. Probe tips used in force microscopy can provide imaging of structure and dynamics of adsorbate at the nanometer scale. Self-assembled functionalized organic thiols on the surface of Au coated Si3N4 probe tips have been used to study the interaction between molecular groups. Again, carbon nanotube probe tips in conjunction with AFM can be used for probing crevices that occur in microelectronic circuits with improved lateral resolution. Functionality modified probe tips have been to measure the binding force between single protein-ligand pairs. Probe tips have been used as a tapping mode technique to provide information about the elastic properties of materials. Probe tips are also used in the mass spectrometer. Enzymatically active probe tips have been used for the enzymatic degradation of analytes. They have also been used as devices to introduce samples into the mass spectrophotometer. For example, trypsin-activated gold (Au/trypsin) probe tips can be used for the peptide mapping of the hen egg lysozyme. Atomically sharp probe tips can be used for imaging a single atom in a molecule. An example of visualizing single atoms in water cluster can be seen in Fig. 10. By visualizing single atoms in molecules present on a surface, scientists can determine bond length, bond order and discrepancies, if any, in conjugation which was previously thought to be impossible in experimental work. Fig. 9 shows the experimentally determined bond order in a poly-aromatic compound, which was thought to be very hard in the past.
== References ==