Fabrication of SERS Active Surface on Polyimide Sample by Excimer Laser Irradiation

Abstract

A possible application of excimer laser irradiation for the preparation of surface enhanced Raman spectroscopy (SERS) substrate is demonstrated. A polyimide foil of 125 μm thickness was irradiated by 240 pulses of focused ArF excimer laser beam (λ= 193 nm, FWHM = 20 ns). The applied fluence was varied between 40 and 80 mJ/cm2. After laser processing, the sample was coated with 40 nm silver by PLD in order to create a conducting layer required for the SERS application. The SERS activity of the samples was tested by Raman microscopy. The Raman spectra of Rhodamine 6G aqueous solution (c=10−3 mol/dm3) were collected from the patterned and metalized areas. For areas prepared at 40–60 mJ/cm2laser fluences, the measured Raman intensities have shown a linear dependence on the applied laser fluence, while above 60 mJ/cm2saturation was observed. The morphology of the SERS active surface areas was investigated by scanning electron microscopy. Finite element modeling was performed in order to simulate the laser-absorption induced heating of the polyimide foil. The simulation resulted in the temporal and spatial distribution of the estimated temperature in the irradiated polyimide sample, which are important for understanding the structure formation process.

Laser‐induced surface structures on gold‐coated polymers: Influence of morphology on surface‐enhanced Raman scattering enhancement

“…Figure shows in detail the topography of the gold layer coating a flat and a nanostructured polymer film and constituted by gold nanoparticles with sizes of up to a few nanometers. Noble metal nanoparticles obtained by PLD have been previously shown to enhance the Raman signal, and this effect was attributed to the relatively high fraction of “hot spots,” localized in the junctions . In our case, the enhancement by eight orders of magnitude of the Raman signal can be attributed to the large number of hot spots in a highly packed nanoparticle metal layer.…”

Analysis of the effect of different laser beam technology parameters when cutting stainless steel sheets with ytterbium fiber laser machine

“…Here, in addition to traditional cutting methods, modern cutting methods must be used, the operation of which is economically maximized both in terms of the machine and in terms of the yield of the raw material [1,2]. There are a number of conditions to consider during laser cutting, some of which are: laser beam power, power density of the laser beam, the focal length of the focusing lens, material and thickness of the plate to be cut, the distance between the cutting gas nozzle and the surface of the plate, the position of the axis of the laser beam relative to the surface normal of the plate [3][4][5][6][7].…”