NanoScan: Nano Single Cell Analysis

Introduction

The goal in this project is to develop a microsystem for performing analysis on single cells by means of nanoneedle technology.

Microsystems used for biological cell research is an intriguing and upcoming research field. Due to the scaling down of dimensions in microsystems the dimensions are getting more suitable for biological cells. Dimensions in the sub-micro, or even in the nanometer range, make it very well possible to do in vivo cell research on single cells. Nano Single Cell Analysis could achieve new insights in the biological or medical research.

Needle systems

Needles in cells are not new, in vitro fertilization has been performed over decades. The cell membrane of female egg cell is penetrated by a hollow needle and a sperm cell is released inside the egg cell.

What is new in this project is the size of the dimensions, the fabrication technology and the extraction of a cell sample. Where egg cells have typical sizes of 100 µm, we aim on normal sized cells of about 8 – 10 µm. Besides that, the whole system will be produced by means of silicon clean room technology. And, instead of the classical in vitro fertilization, the system will not only be capable of cell injection, but also in sample extraction. The needles are connected to an on-chip femtodosing system, which makes it possible to dose amounts of liquid in the femtoliter range. This femtodosing system is driven by electrolysis. This gives high expectations for chemical single cell analysis.

Additionally, needles also can be equipped with an isolated electrode system for performing electrophysiology measurements. Cell potential and cell membrane impedance measurements can be performed on single cell level, which gives new possibilities for biological cell research.

We have produced first prototypes of NanoScan-chips, equipped with hollow needles as well as electrophysiology needles. In Figure 1a, planar microneedles can be seen. This needle has a height of only 260 nm. In Figure 1b, a planar nanoneedle with an inner channel with a height of only 150 nm is shown. Figure 1c shows a planar nanoneedle equipped with an isolated nano-electrode.


Figure 1a. Three planar Silicon micro-needles	Figure 1b. A hollow planar nanoneedle. Height of the inner channel only 150 nm	Figure 1c. A planar electrophysiology nanoneedle. Thickness of the electrode is only 60 nm.

Now we are working on the design and fabrication of the second generation of the NanoScan-systems. Improvements will be made on the needles, electrodes as well on the femtodosing system. Real cell measurements will be performed in the near future.

Interested?

If you are interested and for instance would like to do your graduation work or practical term, please contact via the email address below.

This project is sponsored by the Technology Foundation STW via the Simon Stevin-meesterschap price awarded to Prof.dr.ir. A. van den Berg in 2002.

Contact information

Albert van den Berg

MESA+ Institute for Nanotechnology

University of Twente

P.O. Box 217

7500 AE Enschede

The Netherlands

Phone: +31 (0)53 489 2691

Fax: +31 (0)53 489 3595

E-mail: a.vandenberg@ewi.utwente.nl