Thaindian News

Washington, Feb 17 (ANI): Researchers at Harvard University have developed a scalable and reusable optical detection system that takes scientists one step closer to putting the capacity of a large laboratory into a micro-sized package.

With the help of a combination of high performance optics with microfluidics, the researchers have made lab-on-a-chip technologies more practical.

Microfluidics, the ability to manipulate tiny volumes of liquid, is at the heart of many lab-on-a-chip devices.

Such platforms can automatically mix and filter chemicals, making them ideal for disease detection and environmental sensing.

The performance of these devices, however, is typically inferior to larger scale laboratory equipment.

While lab-on-a-chip systems can deliver and manipulate millions of liquid drops, there is not an equally scalable and efficient way to detect the activity, such as biological reactions, within the drops.

The Harvard team’s zone-plate array optical detection system may offer a solution.

The array, which integrates directly into a massively parallel microfluidic device, can analyze nearly 200,000 droplets per second; is scalable and reusable; and can be readily customized.

“In essence, we’ve integrated some high performance optics onto a chip that contains microfluidics as well. This allows us to be able to parallelize the optics in the same way that a microfluidic device parallelizes sample manipulation and delivery,” said Ken Crozier, an Associate Professor of Electrical Engineering at the Harvard School of Engineering and Applied Sciences (SEAS) who directed the research.

Unlike a typical optical detection system that uses a microscope objective lens to scan a single laser spot over a microfluidic channel, the team’s zone-plate array is designed to detect light from multiple channels simultaneously.

In their demonstration, a 62-element zone-plate array measured a fluorescence signal from drops traveling down 62 channels of a highly parallel microfluidic device.

“Our approach allows us to make measurements over a comparatively large area over the chip. Most microscopes have a relatively limited view and cannot see how the whole system is working. With our device, we can place lenses wherever we want to make a measurement,” said Crozier.

The system can detect nearly 200,000 drops per second, or about four times the existing state-of-the-art detection systems.

Further, the lens array is scalable, without any loss in efficiency, and can be peeled on-and-off like a reusable sticker.

Ultimately, the integrated design offers the sensitivity of a larger confocal microscope and the ability to measure over a larger area, all in a much smaller, cheaper package. (ANI)