• 제목/요약/키워드: Ag colloids

검색결과 12건 처리시간 0.019초

Preparation of Silver Nanocolloids Using Silver Alkylcarbamate Complex in Organic Medium with PVP Stabilizer

  • Park, Hyung-Seok;Park, Heon-Su;Gong, Myoung-Seon
    • Bulletin of the Korean Chemical Society
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    • 제31권9호
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    • pp.2575-2580
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    • 2010
  • We present a method for chemically reducing silver alkylcarbamate complex with hydrazine to synthesize silver nanocolloids in an organic solvent using polyvinylpyrrolidone (PVP) as the stabilizer. To determine the optimal conditions for preparing stable silver colloids of controlled size and shape, the silver 2-ethylhexylcarbamate (Ag-EHCB) complex, PVP, hydrazine, and 2-propanol solvent concentrations in the reaction mixture were varied. The initial colloid has a mean particle diameter of 5-80 nm, and it exhibits an absorption band with various shapes in the UV region with a maximum near 420 nm. UV-vis spectroscopy, TEM, and X-ray diffraction techniques were used to investigate the formation and growth process of the metallic silver nanocolloids.

Copper micro/nanostructures as effective SERS active substrates for pathogen detection

  • Ankamwar, Balaprasad;Sur, Ujjal Kumar
    • Advances in nano research
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    • 제9권2호
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    • pp.113-122
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    • 2020
  • Surface-Enhanced Raman Scattering (SERS) spectroscopy is a multifaceted surface sensitive methodology which exploits spectroscopy-based analysis for various applications. This technique is based on the massive amplification of Raman signals which were feeble previously in order to use them for appropriate identification at qualitative and quantitative in chemical as well as biological systems. This novel powerful technique can be utilized to identify pathogens such as bacteria and viruses. As far as SERS is concerned, one of the most studied problems has been functionalization of SERS active substrate. Metal colloids and nanostructures or microstructures synthesized using noble metals such as Au, Ag and Cu are considered to be SERS active. Silver and gold are extensively used as SERS active substrates due to chemical inertness and stability in air compare to copper. However, use of Cu as a suitable alternative has been taken into account as it is cheap. Herein, we have synthesized air-stable copper microstructures/nanostructures by chemical, electrochemical and microwave-assisted methods. In this paper, we have also discussed the use of as synthesized copper micro/nanostructures as inexpensive yet effective SERS active substrates for the fast identification of micro-organisms like Staphylococcus aureus and Escherichia coli.