Fighting Microbial Warfare With Silver Nanoparticles

Nanotechnology is currently being used as a valuable weapon for combating body odor-causing bacteria. Materials can be manufactured at the ‘nano’ scale, one billion times smaller than the world of meters we currently live in. Nanoparticles provide terrific driving forces for diffusion, which allow s chemical reactions to occur at a high rate. In the case of odor-resistant clothing, the textile industry recognizes that silver nanoparticles offer distinct properties that combat bacterial growth and reduce body odor. Although nanoparticles can provide tremendous benefits, the potential effects on our health and environment still remains unknow n. Some of the primary concerns include the possibilities of nanoparticles penetrating skin and leaking into water systems. Thus, it is crucial for researchers to perform further studies in order to completely understand the impact of nanoparticles on our lives and the environment.

The term “nanoparticle” refers to any particle ranging from 1 to 100 nanometers in size, where a nanometer is one-billionth of a meter. To put the size of a nanoparticle in perspective, the diameter of a human hair is equivalent to 80,000 of the smallest nanoparticles combined. So what makes this miniature particle so popular in the scientific community? A single nanoparticle may not be not sufficient to make an impact, but a billion or even a trillion of these nanoparticles can be pow erful and beneficial to mankind. Scientists have worked with nanoparticles for centuries. Prior to the recent development of advanced microscopes, such as the Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM), scientists had faced significant limitations in their research due to the inability to see the structure of the nanoparticles. Today, the textile industry has integrated nanotechnology into novel products. Odor-resistant clothing, one of the current consumer products on the market, incorporates silver nanoparticles to help minimize the undesirable odor that results from bacteria in sweat and dirt (Fig. 1).

What’s That Smell?

 A Scanning Electron Microscopic (SEM) picture of silver nanoparticles loaded on grafted cotton fabric.
Figure 1 : A Scanning Electron Microscopic (SEM) picture of silver nanoparticles loaded on grafted cotton fabric.

Most people believe body odor is an embarrassing, direct result of sweating or certain body traits. How ever, sweat itself is odorless. Body odors are actually caused by bacterial activity. Many microorganisms, such as bacteria, mold, mildew, and fungus, prefer to grow in moist environments, resulting in an unpleasant smell in our feet or armpits. Thus, bacteria thrive in our sweat glands. When bacteria grow on our body, they decompose sweat into acids that produce the odorous chemicals we perceive as body odor. Propionic acid and isovaleric acid are two common types of acids generated when bacteria break down the human body’s sweat. When amino acids are broken dow n by Propionibacteria into propionic acid, the acid produces a vinegar-like smell. Similarly, Isovaleric acid is produced when the bacteria species Staphylococcus epidermidis breaks dow n fatty acid, causing a cheese-like smell [1].