ИСТИНА

Large-scale self-assembly of metallic nanoparticles (NPs) at electrified liquid-liquid interfaces (LLIs) is the most attractive strategy to obtain plasmonic structures with tuneable optical and electrochemical responses.1 However, this approach has several natural limitations; for example, the potential barrier separated a charged NP from the LLI is too high to overcome by applying the electric field. This barrier is the result of interplaying between the solvation of nanoparticles in the both phases, the interfacial tension and the line tension. Recently, we have developed rapid, scalable and simple method to obtain highly stable continuous gold nanofilms at various liquid-liquid interfaces.2,3 Here, we present extension of that work to LLIs with low interfacial tension with water, such as propylene carbonate (~3 mN∙m–1) and nitromethane (~16 mN∙m–1). Self-assembly of AuNPs at w-MeNO2 interface and the following drain-off of the oil phase leads to formation of colloidosomes (drops of liquid protected by a layer of NPs). Those structures may be used as electrically driven capsules for drug delivery as well as microreactors for SERS analysis of various interfacial reactions. The presence of TTF slightly changed wetting properties of AuNPs and allowed them to cross the interface forming a new colloidal solution of TTF@AuNPs into the oil phase. Such transfer of AuNPs led to their concentration in the PC phase and may be used to form Au-sponges for electrochemical SERS detection. Mentioned above pathways are summarized in Figure 1. Fig.1. Interactions between AuNPs and liquid-liquid interfaces with high (DCE) and low (PC and MeNO2) interfacial tensions with examples of applications: colloidosomes and SERS-active gold-sponges. References: 1. J. B. Edel, A. A. Kornyshev, A. R. Kucernak, and M. Urbakh, Chem. Soc. Rev., 2016, 45, 1581–1596. 2. E. Smirnov, M. D. Scanlon, D. Momotenko, H. Vrubel, M. a Méndez, P.-F. Brevet, and H. H. Girault, ACS Nano, 2014, 8, 9471–9481. 3. E. Smirnov, P. Peljo, M. D. Scanlon, F. Gumy, and H. H. Girault, Nanoscale, 2016, 8, 7723–7737.