Look who’s talking! Not who you’d expect – scientists have devised a way for nanoparticles to communicate with each other.
Communication is an incredibly important part of living. From talking to your mates or at work, to plants letting other parts of their ‘bodies’ know where the sunlight is coming from, it is a massive part of how living things function.
Add on the recent developments of our communication by phones and computers, and you’ll find that we rely heavily on electromagnetic waves for large amounts of our communication. Unfortunately, once devices reach a certain size, they can’t be made any smaller, since they’re limited by the amount of power they need and the size of the electromagnetic wavelengths.
This problem could be solved by nanoparticles, particles small enough that 3,000 could fit along the width of a full stop. However, without communicating, nanoparticles can only perform basic tasks, like storing and converting energy.
“A nanomachine by itself cannot do much,” Josep Miquel Jornet from the University at Buffalo tells New Scientist. “Just like you can do many more things if you connect your computer to the internet, nanomachines will be able to do many, many more things if they are able to interact.”
The team, from the Complutense University of Madrid, the University of Valencia and Polytechnic University of Valencia in Spain, took their inspiration from nature, which solves the communication problem with chemical messengers and hormones. They worked with inorganic nanoparticles called Janus particles, after the Roman god with two faces. The particles too have two faces, one of porous silica carrying a dye, and the other of gold, coated with enzymes.
Two types of these particles, S1gal and S2gox, were dispersed in water, and lactose was added. Enzymes on S1gal hydrolysed the lactose to galactose and glucose (i.e. they broke the lactose down using water), and then the glucose was hydrolysed to gluconic acid by glucose oxidase on S2gox. The glucose was hydrolysed to gluconic acid by the glucose oxidase on S2gox, leading to a pH drop which caused the dye to be released from S1gal. Put simply, the S1gal signalled the presence of S2gox.
“This is one of the first steps toward constructing a nanosized robot,” says Villalonga, who worked on the project. “Our dream is to construct an autonomous nanomachine that can be used to fight cancers.”
The silica side of the nanoparticles could be used to carry medication rather than dye for cancer treatment, or a drug that falls apart too easily outside a cell could be assembled inside the cell by two different nanoparticles. Alternatively, nanoparticles with motors attached could move around the body and communicate to attack an infection or a tumour. Furthermore, communicating networks could be used in computing to create ever smaller computer components.
First, though, scientists will need to work out which molecules are best for which situations. Some scientists also argue that this is not as good as it sounds. The system still can’t be reset, or be used to send more information. Whatever you might think, it’s still a step in the right direction.
“We are attempting to design more complex communication systems,” says Martínez-Máñez. “We are also interested in coupling communication with movement. If nanoparticles can communicate they can behave co-operatively and mimic complex biological behaviours.”