The KSV NIMA Surface Potential Sensor is a compact and highly sensitive characterization instrument that offers complementary data on the packing and orientation of Langmuir films. The KSV NIMA Surface Potential Sensor (SPOT) measures the potential difference above and below the film.
Features & Benefits
The KSV NIMA Surface Potential Sensor measures the potential difference above and below the film and is sensitive to the sum of all the individual dipole moments. The changes in surface potential are measured by detecting the potential difference between the vibrating plate, which is placed above the monolayer, and the counter electrode, which is immersed in the sub-phase below the monolayer.
The sensor allows complementing data from surface pressure—area isotherm measurements obtained from a Langmuir and Langmuir-Blodgett Trough. It allows the determination of monolayer composition, molecular orientation, degree of molecular dissociation and molecular interactions at the interface.
The KSV NIMA Surface Potential Sensor is recommended for use with a KSV NIMA Langmuir, Langmuir-Blodgett or a Microscopy Trough to enable combined surface pressure and surface potential measurements. The KSV NIMA Surface Potential Sensor can also be used with other troughs together with a KSV NIMA Interface Unit. See more details in our compatibility chart below.
Compatibility |
X-Small |
Small |
Medium |
Large |
Liquid-
|
ISR High Compression |
Alternate Large |
Alternate |
SPOT |
– | √ | √ | √ | – | √ | √ | – |
Surface Potential Sensor
Determining effective dipole moments. The sensor can be used to determine effective dipole moments through simple surface potential measurements of a compressed film.
Determining molecular orientation. The provides information about molecular orientation by observing changes in surface potential and combining the data with surface pressure information.
Film electronic structure characterization. Small changes in the electronic structure of molecules can be detected by measuring the change in surface potential.
Molecular structure characterization. Quantify the effects of changes to molecular structure through positional offsets and peak values of the surface potential plots.
Complex formation monitoring. Observe and follow complex formations between monolayers, sub-phase species or adsorbates.
Application examples
The interaction of an antiparasitic peptide with cell membrane models
In drug discovery the permeation of the drug into cells through cell walls and the reaction of the drug within the cell membrane are important factors for drug efficiency. In this example, a drug candidate for the Human African Sleeping Sickness (HAT) was studied in vitro in a model cell membrane.
The oligopeptide-based drug S-(2,4-dinitrophenyl) glutathione di-2-propyl ester, has shown activity in the treatment of HAT and was studied in Langmuir monolayer model membrane of DPPC (dipalmitoyl phosphorylcholine), an abundant lipid in the protozoan membrane. The monolayer properties of the drug itself and its interactions with DPPC monolayers were studied with Langmuir equipment (KSV NIMA Langmuir Trough) with a surface potential meter (KSV NIMA SPOT) and polarization modulation surface infrared reflection absorption spectrometer (KSV NIMA PM-IRRAS).