Pulsed laser ablation synthesis of silver nanoparticles with rapid ionophore derivatives for antivirus activities.

Abstract

The world woke up to a deadly pandemic SARS Covid-19 that broke out of Wuhan, China in December 2019. Many drugs were proposed to help in treating this disease. However, at the time, few drugs showed potential effectiveness in curing covid-19. This research proposed the Covid-19 use of ionophores conjugated silver nanoparticle as a potential drug that can be effective because of its antiviral activities. Ionophores allow metal ions to enter the selective cell membrane of a cell. Once silver ions enter the cell, they start disrupting the replication of the virus DNA. Hence, silver plays an important role as a potential ingredient in drugs that can stop the spread of viruses. Pulsed laser ablation synthesis of a silver target placed in a solution was the method employed in this research to develop relatively smaller sized, spherical nanoparticles. In general, pulsed laser ablation synthesis in solution is a low environmental impact technique which does not need metal precursors and reductants and produces colloids of a relatively high purity as compared to chemical methods. The silver nanoparticles were produced by focusing a pulsed laser beam directed on a silver metal target in a liquid medium. As the laser beam hit the silver target a plasma plume is generated, as the evaporated material expands it then cools and condenses, forming nanoparticles. This approach employs the use of a Q-Switched Nd: YAG dual pulsed laser operating at fundamental 1064 nm and second harmonic 532 nm with energy densities in the range of 34.8 J.cm-2 to 37.3 J.cm-2. The lens focuses the pulsed laser which irradiate a silver target surface that is immersed in deionized water. Silver nanoparticles that were produced had comparable sizes, spherical in shape and similar composition. Their nanoparticle surface chemistry allowed them to be easily grafted with doxycycline. The period of irradiation was varied from 5 minutes to 25 minutes per sample to get different qualities ofAgNPs. The average diameter of the silver nanoparticles was 10,6 nm. The AgNPs were prepared and used to synthesise doxycycline silver nanoparticles. The samples of silver nanoparticles formed were characterised using high-resolution transmission electron microscopy (HR-TEM). The identification of the elements in the nano-material composition was done using Energy dispersive X-ray spectroscopy (EDS or EDX), Raman spectroscopy, and UV-VIS was used to confirm the absorption band gap of AgNPs. The silver nanoparticles that were produced was of high quality, free from toxic reagents and could be used for further medical (in-vivo tests).