Antibody biosensor offers unlimited point-of-care drug monitoring

May 16, 2017, Ecole Polytechnique Federale de Lausanne
Graphical summary of science behind antibody biosensor. Credit: Ecole Polytechnique Federale de Lausanne

Being able to monitor drug concentration in the blood of a patient is an important aspect of any pharmaceutical treatment. However, this requires equipment and facilities that are often missing from field healthcare in developing countries, but also inhibits the quality of life for patients elsewhere. EPFL scientists, working through their startup LUCENTIX, have now developed an antibody-linked biosensor that can track drug concentration in the blood by changing its color. The biosensor is incorporated into a full system that can be used in the field or by patients at home. The science behind it is published in Angewandte Chemie.

The lab of Kai Johnsson at EPFL is known for developing biosensors, and the research gave birth to the startup LUCENTIX, which has developed a that allows to easily measure concentrations in their system without need for complex lab systems.

The biosensor is a molecule made up of three components: First, a protein that can bind the drug to be monitored. Second, the light-producing enzyme luciferase. And third, a "tagging" molecule called SNAP-tag, which carries a fluorescent ligand that the protein (the first component) recognizes and binds when no drug is present. This causes a reaction between the luciferase and the fluorescent molecule called "bioluminescent resonance energy transfer" (BRET), which produces a red light.

The recent innovation, carried out by postdoc Lin Xue, involves replacing the binding protein of the biosensor with part of an antibody that has been developed against the target drug. When the biosensor detects and binds the drug in the patient's blood or saliva, the antibody "prefers" to bind this rather than the SNAP-tag's fluorescent ligand. As the ligand is displaced, the BRET reaction is progressively disrupted, and now emits a blue light.

EPFL's video on the new antibody-based biosensor developed by the lab of Professor Kai Johnsson and the startup LUCENTIX. Credit: EPFL

Antibodies are naturally able to identify and bind foreign , turning our immune systems against potential infections. In addition, generating that can specifically identify small molecules like drugs is a routine procedure. This means that the monitoring system can be adapted to virtually an unlimited number of molecules, while patients can carry out the monitoring themselves at home and receive laboratory-level quality information. Current lab methods for doing this are complex and expensive, and reduce the quality of life for patients who have to often be confined within or close to hospitals.

Replacing the with an antibody establishes a general pipeline for the generation of biosensors that can identify a synthetic drug in a patient's blood sample. As proof-of-principle, the EPFL scientists successfully tested the new biosensors against three drugs - methotrexate, theophylline, and quinine - in the lab. The next step will be to optimize the biosensor's sensitivity so that it can accurately detect the nanomolar or even lower concentrations of drugs/biomolecules in clinical samples.

Explore further: New molecule enables quick drug monitoring

More information: Lin Xue, Qiuliyang Yu, Rudolf Griss, Alberto Schena, Kai Johnsson. Bioluminescent antibodies for point-of-care diagnostics. Angewandte Chemie (2017). DOI: 10.1002/anie.201702403

Related Stories

New molecule enables quick drug monitoring

June 8, 2014

Monitoring the drug concentration in patients is critical for effective treatment, especially in cases of cancer, heart disease, epilepsy and immunosuppression after organ transplants. However, current methods are expensive, ...

The light of fireflies for medical diagnostics

July 22, 2015

In biology and medicine, we often need to detect biological molecules. For example, in cancer diagnostics, doctors need quick and reliable ways of knowing if tumor cells are present in the patient's body. Although such detection ...

Biosensor measures signaling molecules within cilia

March 22, 2016

Scientists of the Research Center caesar in Bonn, an Institute of the Max Planck Society, developed a new biosensor, which allows to measure nanomolar levels of the second messenger cAMP. The sensor makes it possible to study ...

Deep sea light shines on drug delivery potential

July 7, 2015

A naturally occurring bioluminescent protein found in deep sea shrimp—which helps the crustacean spit a glowing cloud at predators—has been touted as a game-changer in terms of monitoring the way drugs interact with live ...

Biosensor to detect tumors at early stages

January 12, 2017

Before a malignant tumor develops, the immune system tries to fight against its altered proteins by producing certain cancer antibodies. A biosensor developed by scientists from the Complutense University of Madrid is able ...

Recommended for you

A protein that self-replicates

February 22, 2018

ETH scientists have been able to prove that a protein structure widespread in nature – the amyloid – is theoretically capable of multiplying itself. This makes it a potential predecessor to molecules that are regarded ...

Newly designed molecule binds nitrogen

February 22, 2018

Wheat, millet and maize all need nitrogen to grow. Fertilisers therefore contain large amounts of nitrogenous compounds, which are usually synthesised by converting nitrogen to ammonia in the industrial Haber-Bosch process, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.