Defense of the doctoral thesis of BANGE Romain, for the University Grenoble Alpes, speciality " NANO ELECTRONICS & NANO TECHNOLOGIES ", entitled:
Amphi M001 (RDC) - Phelma/Minatec
3 rue parvis Louis Néel
38016 Grenoble cedex1
Realization and optimization of biosensors based on SiC nanostructures for the electrical detection of DNA
Monday, February 18, 2019 at 10:30
biosensor, DNA, transistor, field effect, nanowire, silicon carbide
Sensing of low concentrations of nucleic acids is essential to a variety of applications such as bio-medical analysis, in which case it allows the diagnosis of pathologies by identifying specific biomarkers. Compared to traditional sensing techniques based on biochemistry, the advantage of electrical field-effect detection is that it relies on a direct, label-free, and fast-response measurement. Transistors based on semiconducting nanowires are promising devices that theoretically enable very low detection limits and a high sensitivity, thanks to their high surface-to-volume ratio and unique electronic properties. Silicon carbide (SiC) is a semiconductor material with qualities such as very high physical and chemical stability and high biocompatibility, which make it particularly suited for aforementioned applications.
In this thesis, field-effect transistors based on Si and SiC nanowires were designed with a top-down approach to be fabricated using photolithography techniques. The Si-based process was developed and optimized in order to fabricate reproducible devices made of nanowires and nanoribbons. A detailed study was conducted to demonstrate the superior chemical stability of SiC nanowires over Si nanowires under physiological conditions. Based on these results, we investigated two ways of elaborating a thin SiC layer around these Si nanostructures to provide them with its chemical resistance in liquid medium. These reproducible core-shell Si/SiC devices were eventually functionalized and integrated into a microfluidic system in order to achieve novel measurements of DNA detection in real time and in liquid media.