Figure 2.

(A) Application of graphene oxide modified with ATP aptamer conjugated to nucleic acid-stabilized silver nanoclusters (AgNCs) as a hybrid system for the analysis of ATP. The fluorescence of the AgNCs is quenched in the aptamer/graphene oxide hybrid structure and it is switched on upon the desorption of the AgNCs-ATP aptamer/ATP complex from the graphene oxide support. (B) Fluorescence spectra generated upon desorption of the AgNCs-ATP aptamer/ATP complex in the presence of different concentrations of ATP for a fixed time-interval of 1 h. a = 0 mM; b = 0.025 mM; c = 0.05 mM; d = 0.25 mM; e = 0.5 mM; f = 1 mM; g = 2 mM; h = 3 mM. Inset: derived calibration curve. Reproduced with permission from ref. [91]. Copyright 2013 American Chemical Society. Arrows: the arrows correspond to typical excitation and emission arrows.