Vladyslav Mishyn's thesis

The role of surface chemistry on the performance of graphene-based biosensors

Oral defence on 9 December 2021 at 2pm
IRCICA Amphitheatre - Villeneuve d'Ascq

Jury :

Henri HAPPY, Professor, University of Lille, Thesis supervisor
Sabine SZUNERITS, Professor, University of Lille, Thesis co-director
Thomas DONEUX Lecturer, Université Libre de Bruxelles, Rapporteur
Christophe VIEU, Professor, University of Toulouse, Rapporteur
Wolfgang KNOLL, Professor Austrian Institute of Technology, Examiner
Rabah BOUKHERROUB, Research Director, University of Lille, Examiner

Summary:

Clinical analysis benefits worldwide from a variety of diagnostic tests. Interest in developing new clinical tests stems partly from the need to detect new analytes such as viruses and biomarkers, and partly from a strong demand to reduce the cost, complexity and excessive analysis times of current techniques. Among the many possibilities available today, point-of-care (PoC) devices incorporating graphene and its derivatives are key players. The aim of this work is to study and compare the potential of reduced graphene oxide (rGO) and graphene formed by chemical vapour deposition (CVD) for electrical and electrochemical transduction PoC devices. The complete development of biosensors, from the fabrication of graphene-based transducers to the detection of biological molecules, is presented. Emphasis will be placed on the choice of receptors grafted onto the graphene surface. In this context, non-covalent grafting of receptors using different pyrene-based ligands and covalent grafting using 4 - ((triisopropylsilyl) ethylenyl) benzene diazonium salts will be demonstrated and compared. The detection examples discussed are based on the detection of the E7 capsid protein of the human papillomavirus (HPV) and on the level of cardiac troponin I (cTnI) associated with cardiovascular disease, in various biological samples.

Abstract:

Clinical analysis benefits world-wide from a variety of diagnostic tests. The interest in the development of new clinical tests is not only driven by the demand to sense new analytes such as viruses and biomarkers, but also to reduce costs, complexity and lengthy analysis times of current techniques. Among the numerous of possibilities available today, point-of-care (PoC) devices incorporating graphene and its derivatives are prominent players. This work aims at investigating and comparing the potential of reduced graphene oxide (rGO) and graphene formed by chemical vapor deposition (CVD) for electrical and electrochemical based PoC devices. The full biosensor manufacturing process from manufacturing of the graphene-based transducers to sensing biological molecules is described. A focus will be on the choice of the surface receptors anchored onto graphene material. In this context, non-covalent receptor attachment using different pyrene-based ligands and the interest of covalent attachement via 4-((triisopropylsilyl)ethylenyl)benzene diazonium salts will be demonstrated and compared. Sensing examples discusses are based on the detection of the E7 capsid protein of the human papillomavirus (HPV) and the level of cardiac troponin I (cTnI), associated with cardiovascular diseases, in different biological samples.