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Scanning ion conductance microscopy has been evolving into scanning capillary microscopy.
Теги: cканирующая ион-проводящая микроскопия cканирующая капиллярная микроскопия scanning capillary microscopy scanning ion conductance microscopy scanning probe microsocpe зондовая микросокпия
3 February 1989 the journal "Science" published an article by Paul Hansma and co-authors "Scanning Ion Conductance Microscope" [1]. Two days before this Hansma has applied for a patent with the same name [2]. Scanning ion conductance microscope (Fig.1.) became another successful type of devices in the family of scanning probe microscopes.
Scanning ion conductance microscope allows to observe objects in a liquid (electrolyte) with micron and nanometer spatial resolution. Unlike a scanning tunneling microscope that measure only the conductors, the ion conductance microscope can be used for both conductors and insulators. During scanning in an ion conductance microscope, unlike the atomic force microscope, a force impact on the sample is practically absent.
Significant progress in the development and application of scanning ion conductance microscopy has been achieved in the last ten to fifteen years in connection with the development of modulation techniques [3–6] and especially of hopping mode thanks to the researches of Yuri Korchev and co-authors [7, 8]. Exactly the hopping mode allows to fully realize the benefits of scanning ion conductance microscopy. Due to the controlled movement of the needle vertically to the sample at a distance of a few microns it has become possible to study rough objects, which include many biological systems. The use of advanced signal processors and FPGA in combination with high-speed operational amplifiers, analog-to-digital and digital-to-analog converters has enabled to achieve a delicate scan of rough cells, fibers and many other biostructures at high speed without their deformation (Fig.2).
The probe in the form of quartz or a glass capillary in comparison with a conventional cantilever has a smaller convergence angle at the vertex, and hence the broadening of the image is evident in the ion conductance microscopy in significantly lesser extent.
Capabilities of scanning ion conductance microscopy are much broader than just the observation of the surface topography of rough objects with a low mechanical rigidity. The use of multichannel capillaries (Fig.3) as a probe allows multiparametric analysis of cells. Chemical modification of one or several channels of capillary turns the probe into electrochemical nano-sensor [10]. Capillaries with two or more channels also give the opportunity for directed mass transfer of substances of biomacromolecules (peptides, proteins, nucleic acids, etc.) on the surface of the bio-objects or inside their volume.
We can predict the future wide use of ion conductance microscopy in biomedical applications (Fig.4), testing of drugs using only one cell instead of cell culture [11, 12].
The term "scanning capillary microscopy" used for the headline is new for this type of scanning probe microscopy, however, it is advisable to use it. Capillary probe can perform extremely diverse functions of means of delivery, biosensor, electrochemical sensor, pH meter, test system for the detection of metal ions. Scanning capillary microscope fits well in the family of scanning probe microscopes, SPM, where the central letter in the acronym can refer to the type of probe. Thus, scanning capillary microscopy, SCM, occupies a unique place among the methods of probe microscopy.
The project is supported by RFBR (project No. 15-04-07678) and RNA (project 02.G25.31.0135). Thanks to Nanotechnology YICC for the provision of equipment.
Scanning ion conductance microscope allows to observe objects in a liquid (electrolyte) with micron and nanometer spatial resolution. Unlike a scanning tunneling microscope that measure only the conductors, the ion conductance microscope can be used for both conductors and insulators. During scanning in an ion conductance microscope, unlike the atomic force microscope, a force impact on the sample is practically absent.
Significant progress in the development and application of scanning ion conductance microscopy has been achieved in the last ten to fifteen years in connection with the development of modulation techniques [3–6] and especially of hopping mode thanks to the researches of Yuri Korchev and co-authors [7, 8]. Exactly the hopping mode allows to fully realize the benefits of scanning ion conductance microscopy. Due to the controlled movement of the needle vertically to the sample at a distance of a few microns it has become possible to study rough objects, which include many biological systems. The use of advanced signal processors and FPGA in combination with high-speed operational amplifiers, analog-to-digital and digital-to-analog converters has enabled to achieve a delicate scan of rough cells, fibers and many other biostructures at high speed without their deformation (Fig.2).
The probe in the form of quartz or a glass capillary in comparison with a conventional cantilever has a smaller convergence angle at the vertex, and hence the broadening of the image is evident in the ion conductance microscopy in significantly lesser extent.
Capabilities of scanning ion conductance microscopy are much broader than just the observation of the surface topography of rough objects with a low mechanical rigidity. The use of multichannel capillaries (Fig.3) as a probe allows multiparametric analysis of cells. Chemical modification of one or several channels of capillary turns the probe into electrochemical nano-sensor [10]. Capillaries with two or more channels also give the opportunity for directed mass transfer of substances of biomacromolecules (peptides, proteins, nucleic acids, etc.) on the surface of the bio-objects or inside their volume.
We can predict the future wide use of ion conductance microscopy in biomedical applications (Fig.4), testing of drugs using only one cell instead of cell culture [11, 12].
The term "scanning capillary microscopy" used for the headline is new for this type of scanning probe microscopy, however, it is advisable to use it. Capillary probe can perform extremely diverse functions of means of delivery, biosensor, electrochemical sensor, pH meter, test system for the detection of metal ions. Scanning capillary microscope fits well in the family of scanning probe microscopes, SPM, where the central letter in the acronym can refer to the type of probe. Thus, scanning capillary microscopy, SCM, occupies a unique place among the methods of probe microscopy.
The project is supported by RFBR (project No. 15-04-07678) and RNA (project 02.G25.31.0135). Thanks to Nanotechnology YICC for the provision of equipment.
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