Nanotechnology sometimes sounds like something from a science fiction movie. There is often confusion about what they are and what they do. What they are is simple. The range of things they can potentially do– from treating cancer to giving humans night vision – is wide and exciting.
What are Nanoparticles?
Nanoparticles are particles with dimensions less than 100 nanometers. For reference, a strand of human hair is around 100 micrometers thick – making nanoparticles 1000 times smaller. They toe the line between bulk matter and atomic or molecular structures. Their small size gives them a high surface area to volume ratio – making them perfect for applications like drug delivery, environmental pollution control, energy, and water purification.
How are Nanoparticles Made?
Humans have been making nanoparticles for years, but mostly by accident. Activities like cooking, manufacturing, and travel by car or airplane create and release nanoparticles. There are two approaches for making nanoparticles: a top down approach and a bottom up approach. The top down approach breaks down large materials into nanoparticles. The bottom up approach builds nanoparticles from single atoms and molecules.
Most current methods for producing nano particles are toxic, costly, and not eco-friendly. Nanoparticles have been formed from metals, oxides, semiconductors, polymers and various forms of carbon. The nanoparticles can be many different shapes: spheres, wires, tubes, needles, and others.
Biosynthesized silver nanoparticles could be one of the most important applications of nanotechnology. Silver has been used as an antibacterial for burns, cuts and internal infections since ancient times. It has been also reported to be an anticancer agent.
With silver nanoparticles, the use of silver in healthcare could be more beneficial. Silver nanoparticles have been successfully used against various bacterial strains, including E. coli, S. aureus, and S epidermidis. Silver nanoparticles show very little toxicity to mammalian cells, which makes them extremely advantageous for use in healthcare and environmental remediation.
Nanoparticles from Plants
Like so many other industries, researchers are hunting for a better alternative to creating nanoparticles. Plant based options appears to be the way to go. They are comparatively cheap to produce, nontoxic, readily available, and highly effective.
A 2019 study published in the Green Processing and Synthesis journal looked at using turmeric powder and silver, nickel, and copper salts to form metal nanoparticles. Using the bottom up approach, the silver, copper, and nickel ions were first absorbed by the turmeric powder. The addition of sodium borohydride caused the formation of metallic nanoparticles on the surface of the turmeric powder.
The metal nanoparticles were then studied for their antimicrobial properties. Researchers also looked at how well the nanoparticles reduced nitrophenols and dyes, which are common and hazardous water pollutants. Silver performed the best out of the three metal nanoparticles in all the applications studied. Researchers noted that, unlike copper and nickel, silver was adsorbed both on the surface and inside the turmeric power. This makes silver nanoparticles with turmeric powder extremely stable and the best suited for environmental and biological uses.