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 worldwide from a variety of diagnostic tests. The interest in developing new clinical tests is driven by the need to detect new analytes such as viruses and biomarkers, as well as a strong demand to reduce the cost, complexity and excessive analysis time of current techniques. Among the many possibilities available today, point-of-care (PoC) devices incorporating graphene and its derivatives are major players. This work aims to investigate and compare the potential of reduced graphene oxide (rGO) and chemical vapor deposition (CVD) formed graphene 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. The focus will be on the choice of receptors grafted on the graphene surface. In this context, non-covalent grafting of receptors using different pyrene-based ligands as well as covalent grafting via 4 - ((triisopropylsilyl) ethylenyl) benzene diazonium salts will be demonstrated and compared. The detection examples discussed are based on the detection of the human papillomavirus (HPV) E7 capsid protein and the level of cardiac troponin I (cTnI) associated with cardiovascular disease in different biological samples.