Immobilization of graphene-derived materials at gold surfaces: Towards a rational design of protein-based platforms for electrochemical and plasmonic applications

RIVAS, GUSTAVO A.; BOLLO, SOLEDAD; PRIMO, EMILIANO N.; RUBIANES, MARÍA D.; BOLLO, SOLEDAD; RUBIANES, MARÍA D.; RIVAS, GUSTAVO A.; PRIMO, EMILIANO N.

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2018 vol. 259 p. 723 - 732

0013-4686

This work is focused on the critical analysis of the non-covalent modification of a thiolated-gold surfacewith different grapheneous materials and the covalent attachment of bovine serum albumin (BSA) as amodel protein. The main goal was to find a relationship between the nature and amount of the gra-pheneous nanomaterial, the amount of immobilized protein, and the electrochemical and plasmonicproperties of the resulting platforms. The characterization of the grapheneous nanomaterials (grapheneoxide (GO), GO modified with chitosan (CHIT), (GO-CHIT), and chemically reduced GO-CHIT (RGO-CHIT))was performed by using FTIR, Raman, TGA, Dyn amic light scattering (DLS), UVeVis spectroscopy andz-potential measurements. The characterization of the thiolated-gold surfaces modified with the differentnanomaterials and BSA was performed using surface plasmon resonance (SPR), cyclic voltammetry,electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscopy (SECM). The pHof the grapheneous materials dispersions demonstrated to be a critical parameter to control the assemblyof the nanomaterials and the model protein at the gold surfaces and, consequently, the electroactivityand plasmonics of the resulting platforms. When using GO, the optimum pH is 8.00 while in the case ofGO-CHIT and RGO-CHIT, pHs