Watch disease happen at the speed it actually happens, without interference.
At Leiden University, a team led by Alireza Mashaghi has unveiled the world's first quantum biosensor — a device capable of watching cellular chemistry unfold in microseconds, without disturbing the delicate biological systems it observes. For generations, the fastest and most consequential moments in disease progression have remained invisible, hidden behind the limits of conventional tools and the paradox that observation itself corrupts what is being seen. By anchoring its measurements in quantum physics and nanoscale diamonds, this technology offers science something rare: a way to witness life as it actually is, not as it appears when handled.
- Diseases like muscular dystrophy, cancer, and Ebola hinge on molecular reactions so fast and fragile that no existing tool could observe them without altering their course — until now.
- Traditional biosensing methods force researchers to label cells with dyes or markers, a process that inadvertently disrupts the very biological events they are trying to understand.
- The new sensor uses a diamond smaller than 100 nanometers to detect shifts in a cell's environment through changes in light, producing high-resolution images that reveal not just what changed, but exactly where and when.
- Because no labels or external markers are required, cells behave as they would inside a living body — preserving the authenticity of disease development that pharmaceutical research has long struggled to replicate.
- The Leiden lab is already partnering with drug companies and has set its sights on muscular dystrophy, organ-on-chip models, and eventually patient tissue samples as the next frontiers for the technology.
At Leiden University, researcher Alireza Mashaghi has spent his career chasing the molecular events that drive disease — and now he has a tool capable of catching them. The world's first quantum biosensor, developed with Dutch company QT Sense, can observe chemical reactions inside cells as they unfold in microseconds, faster than any conventional microscope can resolve.
The central problem the technology addresses is as old as biological research itself: the act of observation changes what is being observed. Traditional methods require labeling cells with fluorescent dyes or markers to extract information, but that labeling disrupts the very processes under study. Mashaghi frames the stakes clearly — medicines often target proteins that behave differently depending on where they are inside a cell, and without knowing the precise timing and location of those reactions, treatments can fail or cause unintended harm.
The sensor works by placing a diamond less than 100 nanometers across inside a cell sample. When chemical or physical changes occur nearby, the diamond's light output shifts, generating a signal that reveals what is happening, where, and when. Crucially, no dyes or external markers are needed. The cells remain undisturbed, and disease processes unfold as they would in the body — not under artificial conditions.
For now, the lab works with engineered disease models on experimental chips. But the ambitions reach further: organs-on-a-chip, complex tissue models, and eventually samples drawn directly from patients. Muscular dystrophy has been identified as an early priority. Mashaghi's broader goal is to establish a new global standard for cellular research — one built on the ability to watch disease happen at the speed it actually happens, without interference, and without distortion.
At Leiden University, researchers have installed the world's first quantum biosensor—a machine that can watch cells change in real time, catching chemical reactions that unfold in microseconds, faster than the blink of an eye. The device sits in the laboratory of Alireza Mashaghi, a researcher who has spent his career chasing the molecular events that drive disease. For decades, scientists studying conditions like muscular dystrophy, cancer, Ebola, and dengue have known that crucial biological transformations happen inside cells at speeds that conventional microscopes cannot resolve. Now they have a tool that can see them.
The challenge has always been this: many diseases develop through cascades of chemical reactions occurring within and between cells, but these reactions happen so fast, and in such delicate environments, that observing them is nearly impossible. Traditional methods require researchers to label cells with fluorescent dyes or other markers to extract information—but the act of labeling itself disrupts the very processes being studied. It's like trying to watch a soap bubble without touching it. Mashaghi explains the stakes plainly: medicines often target proteins that regulate cellular reactions, but the same protein can exist in different locations within a cell and trigger different outcomes depending on where it is. Without knowing when and where these reactions occur, treatments may fail or cause unexpected harm. Understanding the precise timing and location of biological events is essential to making medicine work better.
The quantum biosensor installation, developed in collaboration with the Dutch company QT Sense, operates on a principle that sounds almost like science fiction but is grounded in quantum physics and magnetism. Beneath the microscope-like apparatus sit experimental chips containing cells or subcellular structures designed to mimic specific diseases. The sensor observes these samples by tracking an extraordinarily small diamond—less than 100 nanometers across—that sits in the sample and responds to changes in its immediate environment. When chemical or physical changes occur nearby, the diamond's light output shifts in intensity, creating a signal that reveals what is happening. The system records these changes in high-resolution images, allowing researchers to see not just that something changed, but exactly where it changed and when.
What makes this technology revolutionary is what it does not do. Unlike conventional biosensing methods, the quantum sensor requires no labels, no dyes, no external markers. The cells remain undisturbed. The biological processes unfold naturally, as they would in the body. Mashaghi emphasizes this point with clarity: the environments being studied are extraordinarily sensitive, and even the smallest disturbance can alter the outcome. The goal is to observe how diseases actually develop, not how they develop under artificial conditions. By eliminating the need for labeling, the quantum biosensor preserves the integrity of the system being observed.
Currently, Mashaghi's lab uses the installation to study artificial disease models—chips containing cells engineered to simulate specific conditions. But the ambitions extend further. The team is planning future projects to determine whether the technology can be applied to organs-on-a-chip, more complex tissue models that better approximate human biology, or even samples taken directly from patients. The lab is already collaborating with pharmaceutical companies to develop new drugs, and Mashaghi has identified muscular dystrophy as a priority for investigation—a group of disorders in which muscles gradually weaken and deteriorate, a process that unfolds through molecular events the quantum biosensor may now be able to resolve.
Mashaghi's stated goal is ambitious but clear: to establish a new worldwide standard for cellular research. The quantum biosensor represents a shift in what is possible—the ability to watch disease happen at the speed it actually happens, without interference, without distortion. For researchers trying to understand how to treat illness more effectively, that clarity changes everything.
Notable Quotes
Without knowing when and where these reactions occur, treatments may be less effective or lead to unwanted side effects.— Alireza Mashaghi, principal researcher at Leiden University
The goal of our installation is ultimately very simple: to set a new worldwide standard for research within cells.— Alireza Mashaghi
The Hearth Conversation Another angle on the story
Why does it matter that we can see these changes without labeling the cells? Couldn't we just use dyes and accept that they change things slightly?
Because "slightly" is the problem. When you're studying reactions that happen in microseconds, even a small disturbance can cascade into something completely different. You end up watching the dye's effect, not the disease.
So the diamond—it's just sitting there in the cell, and it glows differently when things change around it?
Essentially, yes. It's responding to quantum-level shifts in its environment through magnetism. The light it emits tells you what's happening nearby in real time, with spatial precision.
And this matters for drug development because?
Because many drugs target proteins that do different things depending on where they are in the cell. If you don't know where the protein is acting, you don't know if your drug is actually hitting the right target, or if it's causing side effects elsewhere.
What can they study with this that they couldn't before?
Muscular dystrophy, for one—watching how muscles actually break down at the molecular level. Eventually, human tissue samples. The speed and clarity change what questions you can even ask.
Is this the end of the line for this technology, or is it just the beginning?
It's the beginning. Right now they're using disease models on chips. The real test will be whether it works on actual human tissue, whether it can guide real drug development. That's what Mashaghi is building toward.