Plasma-induced formation of Ag nanodots for ultra-high-enhancement surface-enhanced Raman scattering substrates.
ABSTRACT We report here plasma-induced formation of Ag nanostructures for surface-enhanced Raman scattering (SERS) applications. An array of uniform Ag patterned structures of 150 nm diameter was first fabricated on a silicon substrate with imprint lithography; then the substrate was further treated with an oxygen plasma to fracture the patterned structures into clusters of smaller, interconnected, closely packed Ag nanoparticles (20-60 nm) and redeposited Ag nanodots ( approximately 10 nm) between the clusters. The substrate thus formed had a uniform ultrahigh SERS enhancement factor (1010) over the entire substrate for 4-mercaptophenol molecules. By comparison, Au patterned structures fabricated with the same method did not undergo such a morphological change after the plasma treatment and showed no enhancement of Raman scattering.
SourceAvailable from: Mi Jung[Show abstract] [Hide abstract]
ABSTRACT: Ag nanostructure has been widely used for optical sensing applications for localized surface plasmon resonance (LSPR). Many efforts have been tried to fabricate and control silver nanostructure. The pore diameter of the nanoporous alumina mask with through-holes was controlled by two-time dipping in 5 wt% phosphoric acid at 30°C. Using the nanoporous alumina mask as an evaporation mask, size-controlled Ag nanodot arrays were directly formed on indium-tin-oxide coated glass. With this process, Ag nanodot arrays with different size (42 nm, 60 nm, 80 nm) could be fabricated in periodic patterns with same separation distance of 105 nm. A large area Ag nanodot array was fabricated from the hard-won alumina mask. Their LSPR properties are examined by UV-vis extinction spectroscopy.Nanotechnology (IEEE-NANO), 2012 12th IEEE Conference on; 01/2012
[Show abstract] [Hide abstract]
ABSTRACT: Nanoarchitectonics has gained remarkable importance due to the fabrication of various recent nanostructures with the capability of being used in biomedical science, particularly in cancer diagnosis and treatment. These nanosized structures possess unique physical and optical properties that can be exploited for cancer therapeutics, and so nanoarchitectonics is popularly known as nanomedicine. The goal of this review is to discuss the latest findings in nanostructures research including nanocrystals, nanotubes, nanoshells, nanopillars, nanoballs, nanoflowers, nanorods, nanocontainers, nanobelts, nanocages, nanodiscs, nanodots, nanoprisms, nanoplates, nanorings, nanocubes, nanobranches, nanospheres, nanorattles, nanostars, nanotrees, nanowires, nanowalls, nanodiamonds, nanosheets, layered nanostructures, quantum dots, mesoporous nanostructures etc. in the field of cancer therapy and imaging. This review further highlights brief information about use of radionuclide in cancer. Lastly, different nanoformulations that are available in the market or are under clinical trials for cancer therapy and imaging are discussed.Journal of Nanoscience and Nanotechnology 01/2014; 14(1):828-40. DOI:10.1166/jnn.2014.9014 · 1.34 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Raman scattering (RS) is a widely used vibrational technique providing highly specific molecular spectral patterns. A severe limitation for the application of this spectroscopic technique lies in the low cross section of RS. Surface-enhanced Raman scattering (SERS) spectroscopy overcomes this problem by 6-11 order of magnitude enhancement compared with the standard RS for molecules in the close vicinity of certain rough metal surfaces. Thus, SERS combines molecular fingerprint specificity with potential single-molecule sensitivity. Due to the recent development of new SERS-active substrates, labeling and derivatization chemistry, as well as new instrumentations, SERS became a very promising tool for many varied applications, including bioanalytical studies and sensing. Both intrinsic and extrinsic SERS biosensing schemes have been employed to detect and identify small molecules, nucleic acids and proteins, and also for cellular and in vivo sensing. This contribution gives an overview of recent developments in SERS for sensing and biosensing considering also limitations, possibilities and prospects of this technique.Proceedings of SPIE - The International Society for Optical Engineering 05/2013; DOI:10.1117/12.2021555 · 0.20 Impact Factor