Nov 1, 2007
Biosensor to detect prostate cancer cells
A carbon nanotube electronic sensor was developed to detect prostate cancer cells based on the unique properties of carbon nanotubes, such as nanometer diameter, high aspect ratio, high electrical conductivity and the fact that they are chemically inert. It is clear that detecting cancer at the earliest stage provides the greatest chance of survival. Currently, detection techniques are improving. More patients are being diagnosed with localized prostate cancer and fewer patients are being diagnosed with disseminated disease. The sensor might also be used in the bloodstream to detect the concentration of cancer cells and hence infer the metastatic potential of the cancer. Initial testing showed that a carbon nanotube array electrode could quickly detect prostate cancer cells in solution. This nanotube electrode could be used to form the needle sensor.
The carbon nanotube electronic sensor was developed starting from the synthesis of long, highly aligned carbon nanotubes in the form of towers. The nanotube towers were embedded in a microfluidic channel and LNCaP prostate cancer cells were flowed through the channel. Electrochemical impedance measurements were performed and were able to distinguish different concentrations of cancer cells in the flowing solution. Based on these results, it is expected that the carbon nanotube electronic sensor could be used to develop generic cell-based biosensors to detect different types of cancer and disease. The sensor was developed by the interdisciplinary research team of YeoHeung Yun, Zhongyun Dong, Vesselin N Shanov and Mark J Schulz at the University of Cincinnati, US.
Development of the nanotube biosensor is part of an overall trend towards miniaturization in medicine. Electronic biosensing is attractive because it offers the advantages of a quick response, low cost and ease of use as an additional diagnostic tool to supplement traditional immunoassay procedures. In particular, carbon nanotube electronic sensors offer advantages such as enhanced current density, low detection limits and improved signal-to-noise ratios. The preliminary electrochemical impedance results reported here using deionized water, buffer solution and LNCaP prostate cells indicate that nanotube electrodes and electrochemical analysis can be portable, have disposable electrodes and provide real-time measurements as a lab on a chip. The next step in the research is to functionalize the electrode to capture cancer cells. The sensor can then be tested to detect cancer cells in blood and to predict the metastatic potential of diagnosed prostate tumors. If successful, this sensor could improve the efficiency of point-of-care and clinical testing, and might be used as a remote portable device to screen for different diseases.
About the author
Yeoheung Yun is a post-doctoral fellow working in the nanoworld laboratory at the University of Cincinnati in the US. He is currently interested in high-throughput experimental design and nanotechnology-based systems biology.