Excluding the ion source, an ion mobility spectrometer is fundamentally comprised of drift chamber, ion gate, pulsing electronics, and a mechanism for amplifying and recording ion signals. Historically, the solutions to each of these challenges have been custom and rarely replicated exactly. For the IMS research community few detailed resources exist that explicitly detail the construction and operation of ion mobility systems. In an effort to address this knowledge gap we outline a solution to one of the key aspects of a drift tube ion mobility system, the ion gate pulser. Bradbury-Nielsen or Tyndall ion gates are found in nearly every research-grade and commercial IMS system. While conceptually simple, these gate structures often require custom, high-voltage, floating electronics. In this report we detail the operation and performance characteristics of a wifi-enabled, MOSFET-based pulser design that uses a lithium-polymer battery and does not require high voltage isolation transformers. Currently, each output of this circuit follows a TTL signal with ~20 ns rise and fall times, pulses up to +/− 200 V, and is entirely isolated using fiber optics. Detailed schematics and source code are provided to enable continued use of robust pulsing electronics that ease experimental efforts for future comparison.
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Engineering Particle Size for Multivalent Ion Intercalation: Implications for Ion Battery Systems
- Award ID(s):
- 1752517
- PAR ID:
- 10317734
- Date Published:
- Journal Name:
- ACS Applied Nano Materials
- ISSN:
- 2574-0970
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Integration of dual‐barrel membrane patch‐ion channel probes (MP‐ICPs) to scanning ion conductance microscopy (SICM) holds promise of providing a revolutionized approach of spatially resolved chemical sensing. A series of experiments are performed to further the understanding of the system and to answer some fundamental questions, in preparation for future developments of this approach. First, MP‐ICPs are constructed that contain different types of ion channels including transient receptor potential vanilloid 1 and large conductance Ca2+‐activated K+channels to establish the generalizability of the methods. Next, the capability of the MP‐ICP platforms in single ion channel activity measurements is proved. In addition, the interplay between the SICM barrel and the ICP barrel is studied. For ion channels gated by uncharged ligands, channel activity at the ICP barrel is unaffected by the SICM barrel potential; whereas for ion channels that are gated by charged ligands, enhanced channel activity can be obtained by biasing the SICM barrel at potentials with opposite polarity to the charge of the ligand molecules. Finally, a proof‐of‐principle experiment is performed and site‐specific molecular/ionic flux sensing is demonstrated at single‐ion‐channel level, which show that the MP‐ICP platform can be used to quantify local molecular/ionic concentrations.
- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1021/acsanm.1c04360
