Figure 7.

Three applications of cationic NCs are presented here. (a) Induced homogenous aggregation: mixing positively and negatively charged NCs in optimized ratios leads to homogeneous flower-like structures. The main TEM scale bar is 50 nm, and the inset scale bar is 25 nm. (b) Alternating charge layer-by-layer deposition: the peak photoluminescence intensity of the glass substrates progressively increases after each coating (5 layers total). The inset shows a glass substrate containing 3 layers under UV light. (c) Cellular imaging in DIC and fluorescence modes: HeLa cells incubated with CdSe/CdS–TMABr for 30 min (left) and CdSe/CdS–TMABr and HS-PEG₅₅₀ for 10 min (right). Scale bars are 50 μm.