Characterization of HPC‐based photoreduced SERS substrates and detection of different organic dyes

Abstract

Silver nanoparticles were fabricated in situ in the hydroxypropyl cellulose (HPC) matrix by irradiation at different wavelengths (365 and 254 nm) following the principles of green chemistry. HPC is involved in the silver reduction process and in the stabilization as well. Characteristics of the dispersions depend on the weight ratio between silver ions and HPC, irradiation time, and energy of the incident irradiation. Interaction at higher energies leads to higher degradation of the HPC matrix, resulting also in lower pH values of the dispersion. The latter is even more pronounced when using lower initial concentrations of silver nitrate. Different formulations were tested as surface‐enhanced Raman scattering (SERS) substrates with alizarin solutions and several other probes. Different spectral responses are related to different surface availability and/or to differences in microenvironment or macroenvironment of the nanoparticles. Substrates irradiated at lower energies show superior properties in terms of stability, whereas the substrates with a lower concentration of silver ions and irradiated with higher energies are more suitable for the detection of compounds with acidic properties (such as carminic acid and lac dye) due to lower electrostatic repulsion between the compounds and nanoparticles.

SERS procedure using photoreduced substrates and reflection FTIR spectroscopy for the study of natural organic colourants

“…Previous use of the photoreduced substrates already showed promising results for the study of organic colourants. [ 26,30 ] Furthermore, as already showed in our previous research, [ 31 ] preparation of the substrates is easy, and on the other hand, the properties of the HPC‐based photoreduced substrates could be tailored according to variations in preparation parameters, such as the energy of incident UV‐light, weight ratio between silver ions and HPC and time of irradiation, which affect the characteristics of the substrates. Variations in preparation could subsequently optimise the analysis.…”

“…More details on the substrate characterization could be found elsewhere. [ 31 ] The substrate had the absorbance maximum and full width at half maximum (FWHM) of the surface plasmon resonance band at 419 and 118 nm, respectively.…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XIII

“…Retko and co‐workers described the characterization of high‐performance computing‐based photoreduced SERS substrates for the detection of different organic dyes. They tested different formulations as SERS substrates with alizarin solutions and several other probes . Shaikh et al have grown AgNPs having different size and coverage on a large area glass substrate using the low‐cost successive ionic layer adsorption and reduction method.…”

“…They tested different formulations as SERS substrates with alizarin solutions and several other probes. [19] Shaikh et al have grown AgNPs having different size and coverage on a large area glass substrate using the low-cost successive ionic layer adsorption and reduction method. They report that measured relative standard deviation values of AgNPs grown with optimum successive ionic layer adsorption and reduction parameters suggest an excellent homogeneity and reproducibility of the SERS signal.…”

Fourier transform‐Raman and surface‐enhanced Raman spectroscopy analysis of safflower red‐dyed washi paper: pH study and bands assignment

“…The application of ordinary Raman spectroscopy for the characterization of this red dye is limited by the intense fluorescence of the dye and its low solubility in water. Surface‐enhanced Raman spectroscopy (SERS) has proven to be an invaluable tool for the detection and identification of organic substances such as dyes and drugs even in trace levels. Briefly, the adsorption of an organic molecule onto a nanostructured metallic surface results in an extremely significant enhancement of the Raman scattering, accompanied by a remarkable quenching of the fluorescence emission .…”