nanometre = 10-9m
When we talk of creating functional devices, materials and systems by manipulating molecules or atoms, we are talking about nanotechnology. These devices or systems are measured in nanometres. To give you an example 1 nanometre is 100,000 times smaller than the width of human hair.
When designing miniature, self assembled devices we need to have sensors, instructions and assembly devices that will assemble the desired fuctional system. Nano-scale sensors and assembly devices currently exist in nature, they are called antibodies and ribosomes. Fortunately we do not have to start from scratch. We can use and modify what is already present in nature.
Using the cells nanosize machinery, has lead to the first functional nano device to reach the market. This device, the Ambri Ion Channel Switch(ICS™) Biosensor, can detect the presence of specific molecules and signal their presence by creating an electric current. The sensor is composed of a portion of a cell membrane with tethered antibodies. Once the specific molecules bind to the antibody, sodium ion gates open to allow for the sudden flow of positive sodium ions.The more antibodies that are activated the greater the ion flow and hence the greater the current that can be measured. The model mimics the ion gates found in a bacterium. So not only is the presence of target molecules detected but also their concentration.