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Surface-enhanced Raman spectroscopy (SERS) of living cells has rapidly become a powerful trend in biomedical diagnostics. It is a common belief that highly ordered, artificially engineered substrates are the best future decision in this field. This paper, however, describes an alternative successful solution, a new effortless chemical approach to the design of nanostructured silver and heterometallic continuous coatings with a stochastic ''coffee ring'' morphology. The coatings are formed from an ultrasonic mist of aqueous diamminesilver hydroxide, free of reducing agents and nonvolatile pollutants, under mild conditions, at about 200-270 C in air. They consist of 30-100 micrometer wide and 100-400 nm high silver rings composed, in turn, of a porous silver matrix with 10-50 nm silver grains decorating the sponge. This hierarchic structure originates from ultrasonic droplet evaporation, contact-line motion, silver(I) oxide decomposition and evolution of a growing ensemble of silver rings. The fabricated substrates are a remarkable example of a new scalable and low cost material suitable for SERS analyses of living cells. They evoke no hemolysis and reduce erythrocyte lateral mobility due to suitable ''coffee ring'' sizes and a tight contact with the silver nanostructure. A high SERS enhancement, characteristic of pure silver rings, made it possible to record Raman scattering spectra from submembrane hemoglobin in its natural cellular environment inside single living erythrocytes, thus making the substrates promising for various biosensor chips.

A new technique of gold nanoparticle (AuNP) growth on the sidewalls of WS2 inorganic nanotubes (INT-WS2) and the surface of MoS2 fullerene-like nanoparticles (IF-MoS2) is developed to produce metal–semiconductor nanocomposites. The coverage density and mean size of the nanoparticles are dependent on the HAuCl4/MS2 (M = W, Mo) molar ratio. AuNPs formation mechanism seems to involve spatially divided reactions of AuCl4 – reduction and WS2/MoS2 oxidation taking place on the surface defects of the disulfide nanostructures rather than directly at the AuNP-INT/IF interface. A strong epitaxial matching between the lattices of the gold nanoparticles and the INT-WS2 or IF-MoS2 seems to suppress plasmon resonance in the nanocomposites with small (<10 nm mean size) AuNPs.

A machine learning technique, namely, support vector regression, is implemented to enhance single-walled carbon nanotube (SWCNT) thin-film performance for transparent and conducting applications. We collected a comprehensive data set describing the influence of synthesis parameters (temperature and CO 2 concentration) on the equivalent sheet resistance (at 90% transmittance in the visible light range) for SWCNT films obtained by a semi-industrial aerosol (floating-catalyst) CVD with CO as a carbon source and ferrocene as a catalyst precursor. The predictive model trained on the data set shows principal applicability of the method for refining synthesis conditions toward the advanced optoelectronic performance of multiparameter processes such as nanotube growth. Further doping of the improved carbon nanotube films with HAuCl 4 results in the equivalent sheet resistance of 39 Ω/□one of the lowest values achieved so far for SWCNT films.

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