Microfluidic Chip Containing Antibody-Coated Nanoparticles Improves Cancer Detection

A highly sensitive method for detecting cancer can detect single molecules of compounds in blood that signify specific types of tumor.

The technology is based on a microfluidic chip with tiny channels into which a blood sample is drawn. Specially sensitized nanoparticles in the channels capture marker proteins in the blood that indicate certain types of cancer.

The Fraunhofer Institute for Silicate Research (ISR; Wurzburg, Germany) is developing the new diagnostic method to detect cancer in its initial stages so that treatment can start early and improve the patient's chance of recovery. The method should improve cancer detection 100-fold.

Similar testing systems already exist but their measurements are not sufficiently precise, and they can only detect molecules when present in the blood in large quantities. These tests, which must be carried out in a laboratory, are also time-consuming and costly.

Dr Jörn Probst, head of the business unit life science at the ISC explained, "We have placed antibody-occupied nanoparticles on the sensor electrode which 'fish' out the relevant proteins. For this purpose, we repeatedly pump the blood across the electrode surface. As with a river, the flow is fastest in mid-channel and the water runs more slowly near the bank. We have therefore made a sort of fishing rod using nanoparticles which registers the antibodies in the middle of the blood flow where most proteins swim by per unit of time." If an antibody catches the matching protein that indicates a tumor, the electrical charge distribution shifts and this is picked up by the electrode.

The ISC groups are developing a first demonstrator combining four independent single-molecule-sensitive biosensors. They are also working on the simultaneous detection of several tumor markers, which will increase the clarity of tests.

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Fraunhofer Institute for Silicate Research