Nanotechnology is one of the emerging technologies that have the possibility to impact almost every field. At a high level, nanotechnology is making new things at the molecular, or atomic level, at about 1 billionth of a metre. It is the process of rearranging atoms in naturally occurring substances, to make new materials at the nanoscale.
Nanotechnology utilizes this matter for industrialized purposes like medicine, drug discovery, food, security, and water quality. An while there are many different types of nanotechnology, in this article, we are taking a look at nanosensors.
What are Nanosensors?
Nanosensors are sensors, made at nano-scale, that detect what is going on in the microscopic world. There are 2 main types of these sensors: Chemical Sensors, and Mechanical Sensors
Chemical sensors measure the electrochemical changes in the environment
Mechanical sensors measure the force exerted on the sensor itself.
How They Work:
Carbon nanotube sensors work like this:
If nitrogen dioxide is present, it will strip an electron from the nanotube, which in turn causes the nanotube to become less conductive.
If ammonia (NO3) is present, it reacts with water vapour and donates an electron to the carbon nanotube, making it more conductive. By treating the nanotubes with various coating materials, they can be made sensitive to certain molecules and immune to others.
This how the MEMS System (Micro-Electromechanical System) works:
Car airbags depend on this system. These systems have a minuscule weighted shaft attached to a capacitor. The shaft bends with changes in acceleration and this is measured as changes in capacitance.
The Parts of A Nanosensor
- Analyte: what’s being measured
- Sensor: what is analyzing the measurements and detecting. Is coated in different materials to perform/detect different things
- Transducer: converts energy from one to another.
- Detector: gathers the information
The main functions of a nanosensor are sensitivity, specificity, and ease of execution
Nanosensors are made of these things called carbon nanotubes. Carbon nanotubes are cylindrical large molecules consisting of a hexagonal pattern of carbon atoms, which are formed by rolling up a single sheet of graphene into a tube-like shape. They are strong, conductive and lightweight, making them perfect for the job of sensors.
Nanosensors with these nanotubes can measure temperature, pressure, flow, stress, strain, position, displacement, force, chemical concentration
How are these collected?
Carbon nanotubes are made when specific chemical reactions let carbon molecules bond into crystal-like structures, like tubes.
CVD (Chemical Vapor Deposition) uses hydrocarbons and metal catalysts that react under high-temperature conditions, producing carbon nanotubes that stick to the metal particles.
How are nanosensors constructed?
Top-Down Fabrication (Nanolithography)
Some nanosensors can be constructed by sculpting out certain materials from a piece of nanotube and nanomaterial, using precise instruments like high energy light or electron beams. This process is efficient, and pretty fast, but costly.
The bottom-up approach of nanosensor fabrication means precisely aligning nanostructures particle-by-particle to develop nanosensors, almost like building a house with bricks, unlike the top-down approach which is more of a sculpting technique. This approach is cost-effective but slow and largely theoretical (there are a lot of improvements to be made).
Viruses & Bacterias
Nanosensors can also be used in the disease reduction field. Nanosensors latched on antibodies help detect viruses. Basically, the nanosensor uses conductivity to selectively bond with viruses, to measure and track them. This can be used by hospitals to detect bacteria on surfaces
Detecting Airborne Pollution
For this application, nanowires made from a semiconductive material bond with molecules, a change in conductivity, alert sensors. This can be used for detecting high levels of carbon monoxide. This means that we can detect trace amounts of gases in the air, to try to reverse climate change, or just have better carbon monoxide and smoke alarms in our homes.
Measuring Temperature of Cells
“Nano-thermometers” are put into cells, semiconductive crystals change colours depending on temperature. Used for finding temp of tissues and other parts of the body. This helps us regulate cell health, and gives us a possible route of cell research, something that researchers have been searching for a long time.
In the tech world, nanosensors can be used in computers and phones. Nanofluids have enhanced thermal conductivity capabilities; which can help cool down electronics. Nanosensors are needed within these fluids to maintain and detect temperature
Chemical nanosensors detect the chemical or material composition of food, water, environmental, and medical samples to name a few. These nanosensors use sensitive chemical receptors and transducers and can find toxins and chemicals.
NT Sensors — Precision Agriculture Monitoring
This involves the use of precision agriculture nanotechnology sensors that monitor proper macronutrients and water content. The nanosensors provide insights into the ionic strength of the drainage, identify waste points, and aim at increasing crop performance.
Nasys — Air Composition Detection
Nanosensors can detect minuscule amounts of specific gases in the atmosphere. This helps maintain safe living and working conditions and prevent negative health consequences.
The possibilities for nanosensor technologies are endless, with various medical, agricultural, environmental, societal, and military-based opportunities at hand. As previously shown, nanosensors offer significant advantages in cost and response times and are efficient.
Before you go:
I’m Saras, an aspiring innovator, who loves to explore and learn. Student at The Knowledge Society. Science & Tech & Ethics & Philosophy. I also post semi-weekly. Ish. Consider subscribing?