As a representative two-dimensional (2D) nanomaterial, graphene has attracted significant attention in the field of ultrasensitive sensors because of its excellent electronic and chemical properties, and large specific surface area.  In this talk, three different types of graphene-based materials with unique features, i.e., reduced graphene oxide (rGO), crumpled graphene (CG), and vertically-oriented graphene (VG), will be introduced, together with their applications for versatile biosensors based on two major biosensing mechanisms (electronic sensing and electrochemical sensing).  In an electronic biosensor, graphene-based materials are functionalized with gold nanoparticle (NP)-antibody conjugates and used as a conducting channel in a field-effect transistor (FET).  Electrical detection of protein binding is accomplished through FET and direct current (dc) measurements.  In an electrochemical biosensor, highly electrocatalytic metal oxides are combined with graphene-based materials to offer both a high electrocatalytic activity and a high electrical conductivity for enzymeless biosensing.  Biomolecules are then detected through electrochemical measurements such as cyclic voltammetry.  The above-mentioned graphene-based platforms will be demonstrated for the detection of Escherichia coli (E. coli) bacteria, glucose, and various proteins.

As a representative two-dimensional (2D) nanomaterial, graphene has attracted significant attention in the field of ultrasensitive sensors because of its excellent electronic and chemical properties, and large specific surface area.  In this talk, three different types of graphene-based materials with unique features, i.e., reduced graphene oxide (rGO), crumpled graphene (CG), and vertically-oriented graphene (VG), will be introduced, together with their applications for versatile biosensors based on two major biosensing mechanisms (electronic sensing and electrochemical sensing).  In an electronic biosensor, graphene-based materials are functionalized with gold nanoparticle (NP)-antibody conjugates and used as a conducting channel in a field-effect transistor (FET).  Electrical detection of protein binding is accomplished through FET and direct current (dc) measurements.  In an electrochemical biosensor, highly electrocatalytic metal oxides are combined with graphene-based materials to offer both a high electrocatalytic activity and a high electrical conductivity for enzymeless biosensing.  Biomolecules are then detected through electrochemical measurements such as cyclic voltammetry.  The above-mentioned graphene-based platforms will be demonstrated for the detection of Escherichia coli (E. coli) bacteria, glucose, and various proteins.