In-situ carboxylation of graphene by chemical vapor deposition growth for biosensing

A new approach for in-situ specific functionalization of graphene with carboxylic groups through a single-step growth is presented. Depending on the fabrication parameters, it is possible to synthesize functionalized single layer or multilayer graphene. The homogeneity and functionalization degree are evaluated combining micro-Raman and XPS spectroscopies. The obtained COOH content reaches around 5%, similar to the values obtained by the other methods but with significantly lower contents of the other oxygen groups (carbonyl and hydroxyl) and of other sp(3) defects which are detrimental for electronic transport. The obtained COOH-functionalized single-layer graphene presents optimum values of the sheet resistance, around 8 k Omega, and high mobility, around 800 cm(2) V(-1)s(-1). Anchoring of antibodies is demonstrated through the immobilization of IgG1-FITC by the carbodiimide method, showing that these COOH-functionalized single-layer graphene can be very promising materials for electronic sensing applications. (C) 2018 Elsevier Ltd. All rights reserved.