Chemically Custom-Tailored Graphene Could Diagnose HIV With Record Speed

Sometimes technology developed for one application turns out to be great for another. The world is full of beneficial accidents like this. Methylene blue, a dye, turns out to be a useful aid to microbiology and medicine. Ultrasound turns out to be useful for therapy, not just imaging.

Other times, a development is so fundamental that it turns out to be useful in practically everything, such as James Clerk Maxwell’s insights into electromagnetism. The ability to manipulate single atoms has given humans the ability to custom-tailor individually point-flawed diamonds imbued with the characteristics — and only the characteristics — that they desire. And now our ability to handle individual carbon atoms could give us an advantage in the war against diseases like HIV.

We recently covered a piece of slick materials engineering from Spain that you may recall: a silicon-based biosensor-on-chip that could detect HIV in body fluids within seven days of exposure. And it was capable of detecting the virus at orders of magnitude lower concentrations than ELISA. But that’s silicon. We could be using point-doped graphene to accomplish these goals. Stud a flake of graphene with active sites that can grab viral particles, and all of a sudden you have a diagnostic test that only looks for one pathogen because it’s physically incapable of reacting with anything else.

The thing about nanoparticles is that we don’t really have nanomachines yet, so our nanoparticle production tech is still irregular at the actual nanoscale. Have you ever heard “We’d have to be able to manipulate individual atoms” as a way of saying “that’s impossible?” But with the advent of single-atom engineering, and CRISPR at its side, the combination of single-atom precision and custom-tailored antibodies could mean that there’s an application for those tiny Scotch-tape-sized flakes of graphene that we can actually make.

Graphene, in the sizes we can actually make it in.

Currently, HIV testing takes two main forms: rapid testing via cheek swab, and the ELISA blood test that right now carries the global standard for accuracy. Rapid testing is somewhat less accurate, because the “window” during which HIV is not yet detectable in oral fluids extends further in time than does the same window for HIV in the blood.

Because of this, a cheek swab test is a sort of first-line diagnostic test like the rapid strep culture — but there’s a reason they always take a rapid culture and then send the other swab off to be cultured in the lab. Accurate testing takes time. The cheek swab test is highly specific (precise), but less accurate because of timeline differences.

That timeline difference, though, can be a real issue. Suppose a person has contracted HIV. If a person takes a cheek swab too soon after exposure and gets a false negative, their false negative can mean they infect others. Whatever the vector by which they acquired the virus, whether it be sexual contact or contaminated needles or something else entirely, it’s still likely that the person will go back to that environment. But if they don’t know they’re HIV+, no matter how well-intentioned they are, they could be engaging in behavior that puts others at risk of infection.


The silicon HIV-test-on-a-chip did its work by using gold nanoparticles to attract its chosen HIV indicator. Point-doped graphene could use individual gold atoms, for spectacular precision and control.

That’s what makes the rapid results so valuable. Beyond the time commitment and its associated opportunity cost, having a same-day ELISA-quality diagnosis could make a world of difference stemming the infections transmitted before a person knows they need to be taking precautions and informing their partners. For many of the people at highest risk of acquiring HIV, cost is a steep barrier to getting decent health care including HIV and AIDS treatment.

There is good reason for concern that the advance of technology will deepen inequality and lead to more problems, not fewer. But the UN recently announced that they’re gathering member nations to discuss ways to make sure we don’t go down that path. This could be one of those ways: knowing for sure whether you had HIV, on the same day you went in to get tested, would be huge. Who would have thought that graphene could help make that happen?

Now read: What is graphene?

ExtremeTechExtreme – ExtremeTech