Figure 7.

Preparation of nanocomposite-based cytosensors. Precedures for (A) preparing aptamer-DNA concatamer quantum dots by coupling of quantum dot and single-strand DNA followed by hybridization with aptamer and complementary DNAs; (B) preparing Au nanoparticles-modified carbon nanotubes by coating with poly(dopamine) film and Au deposition; and (C) preparing nanocomposite-modified electrodes by successive deposition of Au nanoparticles-modified carbon nanotubes, Con A, and target cells, and aptamer-quantum dots composites on the surface of a glassy carbon electrode. The electrode was immersed in HNO₃ solution to dissolve the residual quantum dots and then the concentration of cells was determined with electrochemical or fluorescence method. Reprinted with permission from Analytical Chemistry. Copyright 2013 American Chemical Society [121].