Review of ultrafast laser ablation for sensing and photonic applications

Abstract

Since its discovery, laser ablation in liquid (LAL) technique has engrossed significant attention from the research community and is gradually becoming a fascinating fabrication technique to synthesize nanostructures (NSs) of diverse morphologies on solid targets as well as nanoparticles (NPs) with distinct shapes/sizes in a single attempt. Moreover, this technique has plethora of advantages over the chemical routes such as simplicity, robustness, and purity of the produced NPs/NSs, as well as the circumvention of stabilizing reagents and/or chemical precursors during the synthesis. The present review focuses on our research group’s significant contributions and achievements over the past 10 years on laser-synthesized nanomaterials (NMs) and their applications in sensing [using the technique of surface enhanced Raman spectroscopy (SERS)] and nonlinear optics (NLO)/photonics. We highlight in the first section the governing mechanisms involved in the LAL technique with laser pulses of different duration such as nanosecond, picosecond, and femtosecond. Subsequent section discusses the effect of input laser pulse parameters (wavelength, fluence, pulse duration, reputation rate, and the number of pulses) as well as surrounding ambience (air and liquid) on the morphological changes of the substrate’s surfaces used in the production of nanoparticles (NPs) and surface nanostructures (NSs). The later section of this review describes the overview of LAL applications with particular emphasis on surface-enhanced Raman scattering based hazardous materials sensing and nonlinear optics/photonics.

Uniform LIPSS on copper created using zeroth-order femtosecond Bessel beam for SERS-based applications

“…Plasmonic nanoelements with single metal/semiconductor/alloy interfaces [5][6][7] have historically been used for sensing-based research and have several important applications in the domain of nanophotonics [8][9]. While several analytical methods [10] have been used in modern times to detect various compounds, sensing using SERS [11][12][13][14] has offered a very impactful, nondestructive, signature way for the majority of hazardous compounds. For this reason, the plasmonic Cu nanostructure was used as a SERS sensor.…”

“…The goal is to identify the SERS response that emerges from the Bessel beam-induced Cu nanostructure's sub-micron surface topography. These SERS substrates have remarkable SERS signal repeatability (less than 20% of RSD), which qualifies them for real-time sensing tasks involving explosive and dangerous chemicals [11][12][13][14][15][16][17][18]. In contrast to Tetryl, where it was discovered to be at 1357 cm -1 [due to NO2 symmetric stretching], PETN had a distinctive Raman peak at 1292 cm -1 [due to NO2 symmetric stretching] [12][13][14][15] Several other observed Raman modes [12] corresponding to these two molecules have been summarized in Table I.…”

“…These SERS substrates have remarkable SERS signal repeatability (less than 20% of RSD), which qualifies them for real-time sensing tasks involving explosive and dangerous chemicals [11][12][13][14][15][16][17][18]. In contrast to Tetryl, where it was discovered to be at 1357 cm -1 [due to NO2 symmetric stretching], PETN had a distinctive Raman peak at 1292 cm -1 [due to NO2 symmetric stretching] [12][13][14][15] Several other observed Raman modes [12] corresponding to these two molecules have been summarized in Table I. We have also presented a comparison (in Table II) of the performance of the Cu NSs with the trimetallic NSs (Ag-Au-Cu) published in our previous report wherein the experiments were performed in similar conditions.…”

“…Xu et al [11] have achieved EFs of ~(10 7 -10 8 ) employing macrocyclic compound functionalized triangular gold nano prisms for the detection of explosive molecule 2,4-dinitrotoluene (DNT). Byram et al [12][13] has extensively worked on gold nanoparticles as well as nanostructures for sensing application. Liu et al [14] fabricated ordered gold nanoparticle arrays and utilized them as surface-enhanced Raman spectroscopy substrates for labelfree detection of nitro explosives.…”

Gold nanostars loaded fabrics as flexible, low-cost SERS substrates and swab-based detection of thiram on fruits and vegetables

“…Surface-enhanced Raman * Author to whom any correspondence should be addressed. scattering (SERS) is a sensing technology that has been widely used in numerous fields, including food safety (such as pesticide residues), disease diagnosis, explosive detection, and more [1][2][3][4][5]. SERS enhancement provides fingerprint information about the analyte at extremely low concentrations [6].…”