Nanomachines for kinetic studies of gene activity in living cells

Like volumes of an encyclopedia, the purpose of genes is to store information. In the same way that books may be taken off a shelf and read, genes are expressed to produce functional RNA and protein molecules inside the cells. All genes in the human genome are not expressed in the same way. Some are expressed in all cells all of the time. Other genes are expressed in particular cell types or at particular stages of development.

A number of human diseases are known to result from the absence or malfunction of transcription factors and the disruption of gene expression thus caused.

The project aims at developing a biosensing system that will be able to follow dynamically specific mRNA expression in living cells cultured in a microfluidic system, something that cannot be done today due to a number of technical limitations.


Figure 1:  Working principle (left) and microfluidic and antenna setup close up (right)

The nanomachine will be constructed based on molecular beacon technology – oligonucleotide probes labeled with a reporter fluorophore and quencher (gold nanoparticle), each one chosen because of its unique properties. The gold nanoparticle act not only as quencher but also as heater. It will be actuated by an RF field that, by induction heating of the metal particle, will reset the molecular beacon to an “off” state, allowing to be ready for another sensing, while keeping the cell alive. This will lead to the possibility of following dynamically processes like down regulation of gene expression.


Figure 2. Melting curves of nanomachines. The machines with 5 bases long stem, melt approximately at 45°, while machines with 11 bases long stem, melt around 65°.

Figure 3. Before (left) and after (right) RF irradiation images of fluorescence emission from nanomachines (calibration phase).

Names: Paolo Della Vedova, PhD student, Mirolyuba Ilieva, PhD student, Ole Hansen, Professor. Martin Dufva, Associate professor.

Affiliation: Silicon Micro-Technology Group, FAST group.

Strategic research field:Biomedical & Life Sciences engineering.