Nanosensors: Fast, Portable and Extremely… tiny

6 min readJul 17, 2019

You may have heard of the term, “nanosensors” before… right? Well, I haven’t and I had only heard of “nano” until just a few days ago, when I started researching it.

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So… what are nanosensors?

What are nanosensors? Well, let’s simplify the large word and break it down into two root words: nano and sensors. A nanometer is a billionth of a meter and a nanogram is a billionth of a gram. Basically they’re just a billionth of a unit. What about the sensors part of “nanosensors”. They sense, right? Particularly, they are nano-devices that detect changes in their environment or specific events in an area of placing.

And, they’re super tiny.

Here is the legitimate definition if you hadn’t yet already searched it up out of curiosity.

A nanosensor can be defined as a device that is capable of conveying data and information about the behaviour and characteristics of nanoparticles at the nanoscale level to the macroscopic level.
From: Nanotechnology Safety, 2013

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Why are nanosensors so important?

Nanosensors are tiny, and they’re so tiny, we do not even know if they’re there or not. Believe it or not, we use them very often in our daily lives, and you’d be thankful we have them, since we are now people of technology.

Nanosensors are used in automatic doorways

Something of the unique things about nanosensors that might come out as mind-blowing for those who are not usually browsing this topic, is that nanosensors can work inside of living cells. Nanosensors can detect chemical and physical properties of particles within bulk materials. They are also extremely sensitive, whilst being a portable-device and a fast reaction. There are many ways in which nanosensors help us, and detecting chemicals in gases are one of them. If they are programmed to detect harmful chemicals in these gases, pollution will be reduced greatly by becoming strict on regulations. It will inspire companies to work with CO2, which many already have worked on. Aside from detecting chemicals, shopping malls equipped with automatic doors use nanosensors for detecting the presence of people and nanosensors aid companies and fields that work with quality management.

“Advances can open unprecedented perspectives for the application of nanosensors in various fields, for example, as molecular-level diagnostic and treatment instruments in medicine and as networks of nanorobots for real-time monitoring of physiological parameters of a human body.”
Jozef T. Devreese, Abstract of Importance of Nanosensors: Feynman’s Vision and the Birth of Nanotechnology

How Do Nanosensors Work?

Four types of nanosensors exist for the moment. Types of sensors include biological, chemical, mechanical and optical sensors. Along with the four types of nanosensors, there are also four components to a sensor system: an analyte, sensor, transducer and detector. If the sensor system is able to discover any particles that it is programmed to detect, feedback is released from the detector into the sensor. The feedback is from electrical changes in the sensor.

Nanosensors being configured for being used in food safety

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How Are Nanosensors Manufactured?

Nanosensors are manufactured by a process called nanofabrication. Nanofabrication is the design and fabrication of nano-scaled objects. Top-down assembly, bottom-up and self-assembly are the most common ways of nanofabrication.

Top-down assembly is similar to how statues are made. There is a large piece of stone and the stone is eroded until the desired shape is made. In nanofabrication, it starts from a blank slate and material is taken away, in accordance to the analogy of the stone sculptor, until the end result of the nanosensor is obtained. For this assembly there are various physical and chemical techniques.

Bottom-down assembly is basically the opposite of top-down assembly. Instead of working from the top to the bottom, you are working from the bottom up. In the context of a brick house, you can say that you have to build the foundation, and work to the roof. This is a long process, as each particle needs to be in the right place, or it will not work out. It also takes much longer than the top-down assembly.

Self-assembly is uncommon, but it is a procedure that is used. To do it right, self-assembly lies in the designing of the elements. Since during self-assembly particles cannot have their properties easily changed, it is more difficult to get the right combinations of particles to get the desired result. It is inefficient and it has many doubts. This can mean that the particles may configure into something different than desired or not react at all.

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What are the problems with Nanofabrication

Nanofabrication requires expensive equipment and facility, highlighting two of its main weaknesses. Though it is very expensive, many companies have begun to fund these projects and have made it more accessible for those who make nano-scaled objects.

For the top-down process for nanofabrication, there is much room for improvemement, especially with measurement. The top-down assembly has worked better with assembling micro-objects (understandable because nano is a billionth, while micro-objects are a millionth). As mentioned previously, since it is like sculpting something out of a large piece of stone, there is definitely going to be more waste. Therefore more equipment would be needed and there would be a financial loss.

Bottom-up assembly has its disadvantages as well, but there are not as many as top-down fabrication though. This assembly does not carry out business processes, and is created through existing materials. This may result in problems after if has problems after it is made, because it cannot be easily changed after its roll-out phase.

Various sorts of Metasurfaces and Plasmonics devices

Ways to Improve The Nanofabrication Process

As a student who is approaching the tenth grade, I am not a person to judge the ways to improve this method, but I will give my best output as a person who is earnest about the industry of nanotechnology.

Top-down assembly could be improved by using smaller machines that are more capable for nanometer sized work in comparison to micrometer sized. This can be easily accomplished through budget raises that can be offered by companies.
Bottom-up assembly could be enhanced by innovating new ways to enhance the product throughout it’s roll-out stage.
Bottom-up assembly should have more research about combinations of different nano-particles and what their impacts are. In other words, there should be studies on this type of assembly, since there is more room for error.
Reducing costs by finding more efficient technology and finding more ways to create nanosensors and other nano-objects.