Confirming the SERS enhancement at large mapping area using self-assembly of silver nanocube at liquid-liquid cyclohexane/water interface

• Main Authors: Jamali, Sain Bux, Khaskheli, Murad Ali, Abro, Mohammad Ilyas, Chand, Ram, Rekik, Najeh, Affan, Hira, Ikram, Rabia
• Format: Article
• Published: Elsevier 2021
• Subjects: QC Physics; QD Chemistry
• Online Access: http://eprints.um.edu.my/28620/

We report silver nanocubes (AgNCs) monolayer constructed using liquid-liquid cyclohexane /water interface at large areas. The self-assembly preparation of the nanoparticles has been conducted by means of a simple straight forward, cheap and less time-consuming evaporation process of solvents. The accessible self-assembled monolayer over the large area on the top of silicon surface has been analyzed by scanning electron microscopy (SEM) whereas the mapping of the nanoparticles monolayer was determined by surface enhanced Raman spectroscopy SERS. The SERS analysis at different mapping area showed that the prepared self-assembled monolayers are uniform, suggesting thereby that the large area of the monolayers on substrates is mainly due to an interfacial electrostatic interaction between the oppositely charged molecules of the hydrophilic nanoparticles. We demonstrate therefore that the obtained nanoparticles can easily aggregate in the mixture of cyclohexane solution and water and, hence can form the self-assembled monolayer. Furthermore, because of the periodic structure at the atomic scale which can be modeled by the Swift-Hohenberg approach and its variants as well as because of its symmetry, the self-assembly of monolayer of AgNCs is studied herein theoretically within the context of pattern selection criteria. Using an ensemble of physically sound parameters, we have seized the main characteristics in the silver nanocube monolayer. A decent agreement between the experimental and the theoretical images is obtained. Due to its rich structural chemistry and remarkably high chemical/thermal stabilities, the combination of cyclohexane/water interface may open new vistas in generating self-assembly of AgNCs with high uniform surface areas and high physical properties. (C) 2021 Elsevier B.V. All rights reserved.