Lab on chip for on-the-spot diagnoses

A European research consortium has shown how to build optical sensors directly into the structure of microfluidic lab-on-chip technology, which could lead to on-the-spot medical diagnostics.

Lab-on-chip technology utilises microfluidics, where tiny volumes of sample liquids move along microscopic channels cut into substances including silicon, glass and plastic. It is then possible to separate samples at the molecular level.

However, relatively large-scale equipment is required to detect and identify the molecules flowing inside the microfluidic chips. The HIBISCUS team said it has solved this problem by ’inscribing’ features into the chips, making integrated optical detection possible for the first time.

The consortium made waveguides using femtosecond laser micromachining to ’draw’ physical features in three dimensions into a thin wafer of glass. The waveguides channel light through the chip, across the microfluidic channels and back out of the chip where it is detected.

It is now possible to shine a light source into the sample fluid and detect its absorption or other optical activity directly in the chip, rather than having to take a sample from the chip and analyse it with laboratory equipment.

Project co-ordinator Giulio Cerullo said lab-on-chip technology can now be shrunk fully, with optical detection and analysis taking place within the chip. Cerullo anticipates lab-on-chip technology helping doctors perform virtually immediate medical diagnoses in their own practices.

The integrated optical detection also makes feasible the idea of using microfluidics as an efficient production method for pharmaceutical products.