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Anastrozole is a well‐known anticancer drug used in aromatase‐dependent cancer chemotherapy as a nonsteroidal aromatase inhibitor. Investigations involving the adsorption of anastrozole on gold surfaces are on demand, because gold nanoparticles (AuNPs) have been used as nanocarriers of drugs, and such a compound can be used against aromatase‐expressing neoplastic cells. In this work, surface‐enhanced Raman scattering (SERS) spectroscopy was used to investigate the interaction between anastrozole and the surfaces of AuNPs. Density functional theory (DFT) calculations were used to simulate the molecular interactions with gold atom through two possible ways, triazole or nitrile moieties. Experimental results, supported by DFT calculations to assign main vibrational modes, indicate that the nitrile groups are the most preferred anchorage moieties for the adsorption. [ABSTRACT FROM AUTHOR] more...

Abstract: Ag nanoparticles having different size and coverage are grown on large area glass substrate (~10 cm2) using low cost successive ionic layer adsorption and reduction (SILAR) method. The SILAR parameters, such as reduction time and growth cycles are optimized to grow Ag nanoparticles with appropriate size and coverage showing maximum surface enhanced Raman scattering (SERS) enhancement of Rhodamine 6 G(R6G). For fixed growth cycles, the size and the coverage of the grown Ag nanoparticles are found to increase with the reduction time and then saturate. The size and coverage of the grown Ag nanoparticles monotonically increase with growth cycles. However, for higher growth cycles, the shape of Ag nanoparticles could not maintain their sphericity and became rock shaped/nonspherical particles, giving rise to intense quadruple plasmon resonance. The growth mechanism is proposed. Further, SERS activity of the grown Ag nanoparticles is studied for an industrial pollutant methylene blue (MB). The observed SERS enhancement factor (~109) for MB is much higher than the reported values in literature. Measured relative standard deviations values of Ag nanoparticles grown with optimum SILAR parameters suggest the excellent homogeneity and reproducibility of the SERS signal. [ABSTRACT FROM AUTHOR] more...

A systematic study was carried out demonstrating that surface concentration is the key factor that must be controlled to overcome the reproducibility problems that has long been haunting surface enhanced Raman spectroscopy (SERS), converting it in a quantitative analytic tool without using any internal standard. The 1,10-phenanthroline molecule (phen) used as model compound can assume different orientations on the surface as a function of surface concentration, but a linear response as a function of concentration was realized in a well-defined range of gold nanoparticles (AuNPs) and phen concentration ratios, allowing to fully explore the very high sensitivity of SERS technique. A detection at a low concentration (5.0 × 10−8 mol dm−3) was achieved controlling the surface concentration in the optimum range where the signals of the species of analytic interest are maximized whilst the signals of all other species are minimized. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR] more...

Surface-enhanced Raman scattering (SERS) in practical application and theoretical research mostly depends on the performance of the SERS substrate. In this study, a new SERS substrate which is based on inverted self-assembly of Ag nanoparticles (AgNPs) on glycidyl methacrylate-ethylene dimethacrylate (GMA-EDMA) porous material is developed. The characterization results show the GMA-EDMA material with intertwined pores may contribute to the distribution of the AgNPs to fabricate an ideal substrate for SERS detection. In view of the characteristics of porous material, an inverted assembly method is proposed and used in operation to avoid the adverse gravity effect which may make the AgNPs plug up the pore channel and distribute on the surface unevenly. By the inverted self-assembly method, the AgNPs could uniformly distribute on the surface of the material stably. The prepared substrate presents ultrasensitivity and good reproducibility for SERS detection. The enhancement factor of rhodamine 6G (R6G) detection is approximately 1014 and the relative standard deviation of each characteristic peak is about 15% when the substrate is used. The substrate also shows a good performance in detecting paraquat and thymine. The ultrasensitive SERS substrate can be readily integrated into pesticide detection systems and biological sample analysis. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR] more...