Size-dependent synergetic seeding effects in the inspection of airborne dry nanoaerosols by LIBS

Different nanoparticle shapes for nanoparticle-enhanced laser-induced breakdown spectroscopy: nanosphere and nanorod effects

“…For these reasons, recently, several studies have been conducted on the use of different colloidal solutions in order to nd the best plasmonic system for specic applications. [6][7][8][9][10] As with most analytical techniques using plasmonic NPs, the size and the shape of the nanostructures play an important role in the setting up of these experiments. 5 In our previous work, 11 the role of the dimension of spherical NPs on NELIBS enhancement with respect to LIBS was studied.…”

Ultrafast Laser Excitation Improves LIBS Performance for the Analysis of Optically Trapped Single Nanoparticles Owing to Characteristic Interaction Mechanisms

“…Therefore, ps-SP-LIBS does not only featured more spectral signatures than conventional ns-SP-LIBS but also allowed the use of those lines for quantification without compromising the detection power of the approach. This can be especially useful in the event of spectral interferences or if the a priori preferred signature is prone to self-reversal, as can be the case for the 324.75 nm Cu­(I) line under some interrogation scenarios . The LOD obtained indicated that the detection power of the OC-OT-LIBS technique was also in the range of attograms when using ultrafast laser pulses.…”

“…The appearance of these emission lines hinted at a potential advantage of using ultrafast excitation for SP elemental characterization: enhanced qualitative capabilities owing to a greater number of analyte-related spectral signatures. Two intertwined arguments may explain the presence of these lines, previously only seen in bulk and aerosol Cu-containing sample analysis . On the one hand, ps spectra featured a significant reduction of the intensity value of the spectral background.…”

“…A fact supporting this claim is that, as in the example provided in Figure A, the 324–327 nm pair of lines was often saturated, as evidenced by the intensity ratio aspect observed between lines, which was different from the ca. 2:1 ratio expected from bibliographical data . Therefore, the closer localization to the particle in conjunction with a reduced spectral background favored the recording of the 510–521 nm triad in the spectrum.…”

“…Furthermore, the electronic temperatures ( T e ) for each size in ps-LIBS were calculated using the following equation: , ln ( λ I A g ) 0.25em = 0.25em ln ( h c N z U z true( T true) ) 0.25em − 0.25em E k K T e where λ is the wavelength of the transition, I is the integrated net intensity of the emission line, A is the transition probability, g is the statistical weight of the upper state, h is Planck’s constant, c is the speed of light, N z is the total number density of the Cu species in the plasma, U z ( T ) is the internal partition function for the Cu(I) atoms at temperature T , E k is the energy of the upper state, and K is Boltzmann’s constant. Exact values used for the calculation of T e are reported elsewhere . It must be noted that plasma local thermal equilibrium conditions must be assumed for the Boltzmann plot to be applicable.…”