Carbon nanopipettes (CNPs) are fabricated by pulling glass/quartz capillaries of about 1mm diameter to form nanotips. The pulled capillaries are then subjected to a chemical vapor deposition (CVD) in the presence of a hydrocarbon precursor gas. In this CVD process, the entire inner surface of the capillary is coated with a carbon film. The duration of the CVD controls the film thickness. Next, the glass at the tip of the carbon coated pipette is etched, leaving behind an exposed carbon pipe that is seamlessly attached to the glass capillary.
The diameter of the carbon pipe can be varied controllably from 10s to 100s of nanometers. This process overcomes a major challenge of nanotechnology: the interfacing between a nanostructure and a macroscopic handle. Since the CNPs can be made hollow, they can be used as nano-injectors. Since the CNPs are electrically conducting, they can be used as electrochemical sensors. Moreover, the carbon coating modifies the mechanical and chemical properties of the glass/quartz tip. The small size of the tip enables cell penetration with minimal damage to the cell.
Applications and Challenges
- Injectors to controllably inject molecules into individual cells to study cell biology and drug efficacy with minimal intrusion
- Nanoelectrodes to carry out electrochemical measurements in and around cells and to sense tip’s position relative to the cytoplamsic membrane
- In-vitro fertilization
- Automated cell injection
Challenges include reproducible production of CNPs with well-controlled dimensions and material properties.
Find additional information on Dr. Bau’s website.
- Kim, B. M, Murray, T., and Bau, H. H., 2005, The Fabrication of Integrated Carbon Pipes with Sub Micron Diameters, Nanotechnology, 16, 1317-1320.
- Schrlau M, Falls, E., M., Ziober, B., L., and Bau, H. H., 2008, Carbon Nanopipettes for Cell Probes and Intracellular Injection, Nanotechnology, 19, 015101 (4p), doi:10.1088/0957-4484/19/01/015101.
- Schrlau M, Brailoiu, E., Patel, S., Gogotsi, Y., Dun, N., and Bau, H. H., 2008, Carbon Nanopipettes Characterize Calcium Release Pathways in Breast Cancer Cells, Nanotechnology 19, 325102. Schrlau, M., Dun, N., and Bau, H. H., 2009, Cell Electrophysiology with Carbon Nanopipettes, ACS Nano 3 (3), 563-568 (nn-2008-00851d.R1)
- Anderson, S., and Bau, H. H., 2014, Electrical Detection of Cellular Penetration during Microinjection with Carbon Nanopipettes, Nanotechnology 25, 245102.
- Hillary R. Rees, Sean E. Anderson, Eve Privman, Haim H. Bau, and B. Jill Venton, 2015, Carbon nanopipette electrodes for dopamine detection in Drosophila. Analytical Chemistry 87(7), 3849-3855, DOI: 1021/ac504596y.
- Anderson, S., and Bau, H. H., 2015, Carbon Nanoelectrodes for Single-Cell Probing, Nanotechnology 26, 185101, doi:10.1088/0957-4484/26/18/185101
- USA Patent 7,824,620, M. Kim and Haim H. Bau, 2010, “Nano- and Micro-scale Structures: Methods, Devices, and Applications Thereof
- USA Patent 7,964,159, Byong Man Kim, Michael Riegelman, Yuri Gogotsi, and Haim H. Bau, 2011, Nanotube-Based Devices for Biochemical Sensing and Processing and for Electron Microscopy of Chemical and Biological Interactions in Liquids and Gases
- USA Patent 8,877,518, Schrlau, M., and Bau, H. H., 2014, Multiplexed Nanoscale Electrochemical Sensor for Multi-Analyte Detection.