By continuing to use the site you agree to our Privacy & Cookies policy

Your browser seems to have cookies disabled. For the best experience of this website, please enable cookies in your browser.


Your browser is no longer supported

For the best possible experience using our website we recommend you upgrade to a newer version or another browser.


Colour changing molecule could help monitor drug dosages

A molecule that changes colour in the blood could provide a simple and accurate way of monitoring drug dosages for patients, say researchers.

The biosensor emits a light that turns gradually from red to blue according to a drug’s concentration.

Ensuring patients get the correct doses of medicines can be critically important, especially in cases of cancer, heart disease and epilepsy, and when suppressing the immune system after organ transplants.

But since patients differ in their tolerance to drugs this can be tricky. Too high a dose can lead to unwanted side effects or even poisoning, while one that is too low might not be effective.

“This system is a cheap, effective solution for customising drug dosage”

Rudolf Griss

Constant monitoring is often needed to get the balance right, which currently involves specialist staff and costly testing equipment in laboratories away from the point of care.

The new molecule is customised to bind to a particular drug and contains other elements designed to emit light and alter its colour.

When no drug is present, it generates a red light, but in the drug’s presence, molecular changes cause the switch from red to blue.

The signal is measured by placing a drop of blood on a piece of paper and photographing it in a dark box with a conventional digital camera.

Colour-measuring software is then used to produce an average reading from which the drug’s concentration in the patient’s bloodstream can be calculated.

The sensor molecule can easily be tailored for use with virtually any kind of drug, said its inventors writing in the journal Nature Chemical Biology.

Dr Rudolf Griss, from the Ecole Polytechnique Federale de Lausanne in Switzerland, said: “This system is a cheap, effective solution for customising drug dosage in patients across a whole array of diseases.

“We envision a simple, hand-held detector where the patient can take a pin-prick of blood and can have an immediate reading of free drug concentration in their system – much like diabetics do now for blood glucose.”

He and a colleague have launched a start-up company to commercialise the product.

Have your say

You must sign in to make a comment.

Related Jobs

Sign in to see the latest jobs relevant to you!