Posted: March 2, 2009

Nanosensors to detect possible mutations in DNA

(Nanowerk News) Researchers at the Cidetec-IK4 technological centre in Spain have developed electrochemical sensors that, amongst other functions, enable the detection of possible mutations in DNA in a more rapid manner that has been achieved to date. The most notable aspect of the developed research is that this detection of DNA has been employed solely as a concept test, to study the viability of sensors. Thus, a wide range of possibilities has been opened for the coming years, in which nanosensors will be able to be applied to detect other types of molecules and even in the study of genetic illnesses.
The scientific magazine Nano Letters, published by the American Chemical Society, has reflected the importance of this research, drawn up by a Cidetec-IK4 team in collaboration with the University of Berkeley and the CSIC in a project for the manufacture of nanosensors, both optical and electrochemical (Label-Free DNA Biosensors Based on Functionalized Carbon Nanotube Field Effect Transistors).
The achievement of this research, and the reason the article was published in NanoLetters, lies in the fact that the el sensor developed employs only a nanotransistor the cable of which is a simple carbon nanotube. This has enabled the detection of non-modified DNA probes.
The sensor detects DNA sequences and, thus, could be employed in genetics and in biotechnology. With certain genetic illnesses, the causal gene is known. Patients with a specific sequence of genes develop a specific disease. What the sensor can do is to detect these specific sequences of DNA given that, by its nature, it is highly selective.
Cidetec-IK4’s innovate activity in this field was to design and synthesise a polymer that enabled the subsequent modification of the nanotube as the DNA anchor, by means of the molecules on the surface of the material. The article shows that, without the polymer, the nanosensor does not function. So, the fundamental contribution of Cidetec-IK4 in the project was to enable the functionalisation of the nanotubes through employing the polymer for the manufacture of the nanosensor.
Equally important to emphasise is that such high sensitivity has been achieved without the need to modify the DNA. In general, electrochemical sensors with high sensitivity usually need the marking of the molecules to be detected in order to increase their sensitivity. In this specific development, the fact of employing carbon nanotubes has enabled carrying out the detection of sequences directly.
Source: Elhuyar Fundazioa