Most Powerful Biosensor System Built With Copper and Graphene Oxide

  • Researchers develop world’s first biosensor chips based copper and graphene oxide. 
  • They’ve standard configuration, and thus are compatible with existing industrial biosensors. 
  • They can be integrated in mobiles, wearable gadgets and even smart clothes.

Biosensors are analytical instruments that convert a biological response into an electrical signal. Usually, a biosensor system contains biotransducer equipment, bio-recognition site, processor, signal amplifier and a display.

The small biosensor chips are used to study the kinetics of molecular interactions, find molecules responsible for a particular disease, and identify dangerous substances in several things, including food and leaks from plants. Also, they are widely used by pharmaceutical companies and organizations to build drugs.

Typically, all biosensor chips are made with nanometer-thick gold sheets, because gold is chemically very stable and has superior optical properties. However, it isn’t a perfect material. One of the major reasons is its cost.

As compared to copper, gold are 25 times more costlier. And, they’re incompatible with commercial processes used for miniaturizing electronics, which limits gold’s potential for most of the applications in device mass production.

Now the researchers at the Moscow Institute of Physics and Technology have developed a new bio sensing chip based on unique materials – copper and graphene oxide. They have achieved an incredibly high efficiency or sensitivity, opening up new paths for development of biosensors. And since most of their configurations are standard, they’re compatible with current industrial biosensors.

Why Copper and Graphene Oxide Instead of Gold?

The optical properties of copper are as good as those of gold. Copper is widely used as an electrical conductor. But like other materials, it isn’t perfect too. It suffers of corrosion or oxidation. That’s the reason it hasn’t been used in biosensor chips until now.

To deal with this issue, researchers covered the copper with a dielectric layer of 10 nm thickness. And it worked very well. In fact, this thin layer slightly changed the chip’s properties, making it ultra-sensitive.

Schematic representation of the surface plasmon resonance biosensor | Courtesy of researchers 

To further improve the design, they added a layer of graphene oxide on top of the dielectric sheet, which made biosensor even more sensitive. Graphene oxide is a graphene — a very thin material made of carbon atoms bonded together in a repeating hexagon pattern — with groups of oxygen attached to some carbon atoms. These groups establish a link between protein molecules (that are being examined) and surface of the device.

Reference: ACSPublications | doi:10.1021/acs.langmuir.8b00276 | MIPT

Also, graphene oxide is cheaper and easier to manufacture than graphene. It has a high surface area, which makes it fit to be used in electrode materials like capacitors, batteries and solar cells.

This is the not the first time researchers have used graphene oxide to enhance biosensors’ sensitivity. In 2015, they described a novel sensor chip for surface plasmon resonance biosensors based on layers of graphene oxide. It had 3 times higher sensitivity than industrial sensor chips.

This time, they have proposed surface plasmon resonance biosensor chips based on a copper− dielectric plasmonic interface. The thin copper sheets support plasmons’ excitation, which can be effectively linked with external laser radiation.

Applications

Since copper chips are compatible with existing microelectronics technology, these biosensors can be integrated in mobiles, wearable devices, gadgets and even smart clothes. These days, giant companies like Samsung and IBM are trying hard to create small sensing chips that could be integrated into their products and motion sensors like a gyroscopes and accelerometers.

Read: Measuring Brain’s Electrical Activity Using Fluorescent Sensor

Moreover, major tech players like Apple, Microsoft and Google are working to implement artificial intelligence in smart gadgets and bio-interfaces that would act as mediators between machine and human brain. Bottom line – we could see a tremendous impact of these biosensors in the future.

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