And if, instead of waiting for weeks an appointment or queuing in the hospital, it was enough for a small unique, inexpensive and without refrigeration sensor, to detect serious illnesses such as cancer or HIV … directly at home? This scenario, worthy of a science fiction film, is about to come true thanks to a surprising innovation out of MIT laboratories.
At the crossroads of biotechnology, chemistry and portable medicine, this disposable sensor could upset our relationship to medical diagnosis. And the most amazing is that it works thanks to … DNA.
A miniature detector that reads the disease in DNA
This electrochemical sensor, developed by the team of Professor Ariel Furst at the MIT, is based on a simple but ingenious principle: it detects the presence of genes associated with certain diseases (such as prostate cancer, HIV or HPV) by monitoring how a special enzyme interacts with strands of DNA fixed on an electrode.
The enzyme in question, baptized case12, comes from the famous CRISPR system, often described as the “genetic scissors” of modern biology. Its particularity? When she meets a target genetic sequence, she becomes overactive and cuts all the DNA that surrounds her. Imagine a lawn mower which, once on, cuts without distinction all the grass nearby. Result: DNA fixed on the sensor electrode is chopped, which modifies the electrical signal of the device. This change is then interpreted by a small portable reader, confirming or not the presence of the disease.
The genius of simplicity: a low-tech but ultra-performance sensor
The real revolution is not only in the functioning of the sensor, but in its simplicity of use and its robustness. Unlike the usual devices requiring a sterile environment or precise conservation conditions, it works without refrigeration. It can be shipped, stored and used even at extreme temperatures, up to 65 ° C.
This technological tour de force is based on a very simple innovation: a polymer coating (polyvinyl alcohol, or PVA), applied to the DNA layer of the sensor. Once dry, this film forms an ultra-fine protective barrier, preventing degradations due to heat, oxygen or humidity. DNA therefore remains stable for more than two months, without the need for a cold chain.
And icing on the cake: the manufacturing cost is only 50 cents per unit.
The sensors consist of DNA glued to an inexpensive gold leaf electrode, laminated on a plastic sheet. Credits: MIT
Home test, accessible to everyone?
In the laboratory, the device has proven its effectiveness on urine samples containing the PCA3 biomarker, associated with prostate cancer. It has also been tested with salivary and nasal samples, and could be easily adapted to identify other viruses, bacteria or genetic mutations. We are talking about an ultra-flexible tool here, programmable according to the target to be detected, simply by changing the RNA guide used by the enzyme case12.
In a world faced with pandemics, inequalities in access to care or overloaded medical infrastructure, this sensor could become a game to change. Imagine being able to carry out an early HIV screening in an isolated village, or follow the evolution of cancer treatment without having to move to the hospital.
From lab to start-up: towards large-scale production
The MIT team does not stop there. Thanks to the validation of this technology, it has embarked on the accelerator of Delta V startups, with the ambition to market these sensors for field tests. Until recently, the sensors had to be made on site, just before their use. Today, they can be produced in advance, transported around the world, and used easily, without any particular expertise.
Ultimately, this innovation could extend to the detection of emerging diseases, or even serve in the event of a health disaster to make rapid diagnostics in the field, on a large scale.
A little revolution in silence
Behind this sensor hides a simple philosophy: democratizing access to health, making it more mobile, faster, and above all more equitable. For Ariel Furst, the goal is clear: “We want to make the diagnosis accessible to people who do not have access to medical structures. It is not only effective, but social impact. »»
If the challenge remains to industrialize it on a large scale and to guarantee its reliability in real conditions, the potential is immense. And it comes down into a promise: transforming a simple piece of plastic and DNA into a silent sentry of our health.
The study is published in the journal ACS
Sensors.
