SURFACE-ENHANCED RAMAN SCATTERING ACTIVITY OF PLASMONIC Ag–Ti NANOISLAND FILMS

Author(s):  
WUTTICHAI PHAE-NGAM ◽  
TANATTHA RATTANA ◽  
SUPPHADATE SUJINNAPRAM ◽  
CHANUNTHORN CHANANONNAWATHORN ◽  
URAIWAN WAIWIJIT ◽  
...  

Bimetallic nanostructure of noble metals is an alternative material that can provide the tenability of plasmonic performance. In this study, the plasmonic silver–titanium nanoisland (Ag–Ti NI) films deposited on a silicon wafer and glass slide substrates were prepared by magnetron co-sputtering of high-purity Ag target (99.99%) operated at 100 W-DC source, and Ti target (99.99%) operated at 50–250 W-DC pulsed source. The surface morphologies of the prepared films revealed a noncontinuous island Ag–Ti according to the formation of thin film growth based on the Volmer–Weber model. An increase in the sputtering power of the Ti target caused an evident increase in the Ag–Ti NIs diameter. The localized surface plasmon resonance (LSPR) was evaluated by UV–Vis–NIR spectrophotometry. The LSPR peak shift disappears with an increase of the sputtering power of the Ti target.In addition, the results confirmed that the surface-enhanced Raman scattering (SERS) activity of the bimetallic Ag–Ti NIs significantly improved in performance and stability, which is promising for the application in analytical chemistry.

2019 ◽  
Vol 73 (6) ◽  
pp. 665-677 ◽  
Author(s):  
Raymond A. Velez ◽  
Nickolay V. Lavrik ◽  
Ivan I. Kravchenko ◽  
Michael J. Sepaniak ◽  
Marco A. De Jesus

The use of nanomachining methods capable of reproducible construction of nano-arrayed devices have revolutionized the field of plasmonic sensing by the introduction of a diversity of rationally engineered designs. Significant strides have been made to fabricate plasmonic platforms with tailored interparticle gaps to improve their performance for surface-enhanced Raman scattering (SERS) applications. Over time, a dichotomy has emerged in the implementation of SERS for analytical applications, the construction of substrates, optimization of interparticle spacing as a means to optimize electromagnetic field enhancement at the localized surface plasmon level, and the substrate sensitivity over extended areas to achieve quantitative performance. This work assessed the enhancement factor of plasmonic Ag/SiO2/Si disc-on-pillar (DOP) arrays of variable pitch with its analytical performance for quantitative applications. Experimental data were compared with those from finite-difference time-domain (FDTD) simulations used in the optimization of the array dimensions. A self-assembled monolayer (SAM) of benzenethiol rendered highly reproducible signals (RSD ∼4–10%) and SERS substrate enhancement factor (SSEF) values in the orders of 106–108 for all pitches. Spectra corresponding to rhodamine 6G (R6G) and 4-aminobenzoic acid demonstrated the advantages of using the more densely packed DOP arrays with a 160 nm pitch (gap = 40 nm) for quantitation in spite of the strongest SSEF was attained for a pitch of 520 nm corresponding to a 400 nm gap.


2014 ◽  
Vol 1625 ◽  
Author(s):  
Jencilin Johnston ◽  
Erik N. Taylor ◽  
Richard J. Gilbert ◽  
Thomas J. Webster

ABSTRACTSurface enhanced Raman scattering (SERS) is a sensitive and reproducible vibrational spectroscopic technique used to detect and characterize molecules near the surface of noble metals like Au, Ag, Pt, Cu, etc. SERS enhances Raman signals through light-induced plasmonic vibrations occurring on irregular metal surfaces and localized electromagnetic augmentation. To better define nano-scale regions of the Raman signal enhancement, we generated gold nanoparticles with a unique multi-branched configuration along with surface-adsorbed fluorescent reporter molecules. The reporter molecules included a set of near-infra red active fluorescent dyes IR820 (green cyanine, photo electronic dye), DTTC (3, 3'-diethylthiatricarbocyanine iodide) and DTDC (3, 3'- diethylthiadicarbocyanine iodide). We employed a one-pot synthesis method in order to generate a stellate configuration in gold nanoparticles through the reduction of HAuCl4 with Good’s buffer, HEPES, at pH 7.4 and room temperature. A cell viability assay was performed with normal esophageal cells exposed to the multi-branched gold nanoparticles and SERS molecules to assess their toxicity. Our results demonstrate the capacity of multibranched gold nanoparticles linked to Raman reporter molecules to generate distinct signature spectra and, with the exception of the gold nanoparticles functionalized with DTTC, remain non-toxic to normal esophageal cells.


2013 ◽  
Vol 754 ◽  
pp. 143-169 ◽  
Author(s):  
Mohammad Kamal Hossain

Although surface-enhanced Raman scattering (SERS) has crossed its infancy long ago, it is yet to persuade different challenges to make it available in day-to-day applications. SERS is being criticized mainly due to the quality of the SERS analyses that uses substrates to get the giant enhancement for respective Raman signal of the target molecule. Hence, understanding the phenomena behind substrates, cost-effective development and optimization of such substrates for routine analytical purposes and utilization of modern modalities to get the insights out has become a very wide-spreading and interesting area of research. In this piece of work, several key terminologies related to SERS have been presented in brief. Since SERS is a localized surface plasmon resonance (LSPR) mediated signal-enhancing phenomena, it is indispensable to understand the correlation between LSPR excitations originated from substrate and SERS signal originated from molecules. A wide range of SERS-active substrates including scattered nanoaggregates, anisotropic assembly, two-dimensional nanostructure, multi-layered nanostructure of gold nanoparticles and colloidal approach have been used to interpret such correlation between LSPR excitations and SERS characteristics. Few exemplary applications of SERS have been also mentioned followed by typical simulative work how nanoobject behaves at different excitations and polarizations.


RSC Advances ◽  
2015 ◽  
Vol 5 (53) ◽  
pp. 42653-42662 ◽  
Author(s):  
Xue Gong ◽  
Jian Tang ◽  
Yixin Ji ◽  
Bingbing Wu ◽  
Huaping Wu ◽  
...  

Colloidal hollow gold nanospheres with adjustable localized surface plasmon resonance (LSPR) properties were synthesized and self-assembled into HGNs monolayers for investigation of LSPR-dependent surface enhanced Raman scattering (SERS) behavior.


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