Figure 12.
(a) Covalent immobilization of neutravidin on the surface of the graphene oxide (GO) linking layer deposited on the copper surface plasmon resonance (SPR) sensor chip protected by 15 nm thick Al2O3 film. The immobilization procedure includes the activation of carboxyl groups of GO by the mixture of 0.4 M 1-ethyl-3-(3-(dimethylamino) propyl) carbodiimide hydrochloride (EDC) and 0.1 M N-hydroxysuccinimide (NHS) solutions and deactivation of carboxyl groups after neutravidin adsorption by 1 M Tris solution. (b) Adsorption of oligonucleotides D1 and D2 on the surface of neutravidin–GO copper SPR chip. D1 is biotinylated and complementary to non-biotinylated D2. PBS: phosphate-buffered saline Reprinted with permission from ref. [79]. 2018 American Chemistry Society.