Fast Camera Takes A New Look at Biosensing

A European consortium comprising the National Physical Laboratory, ST Microelectronics, the University of Edinburgh and TU Delft has been involved in the development and application of the Megaframe Imager - an ultrafast camera capable of recording images at the rate of one million frames per second.

Since the introduction of solid-state optical sensors, such as those found in digital cameras, the main trend has moved toward increasing the resolution (i.e. number of pixels) while miniaturizing the chip.

Megaframe 32 x 32 single photon avalanche diode (SPAD) array fabricated in 0.13 µm STMICRO imaging CMOS technology.

However, the other factor is the number of frames the chip is capable of recording in a given time. Until recently, fast cameras (i.e. those capturing more than the 24 fps required for 'normal' video) were only used in niche markets in science and entertainment.

Now that higher-than-video speeds are achievable, a whole new range of previously unthinkable applications have emerged – such as: cellular / sub-cellular imaging; neural imaging; biochemical sensors; DNA / protein microarray scanning; automotive collision studies; and high-sensitivity astronomical observations.

The Megaframe Imager, which uses an extremely sensitive single photon avalanche diode (SPAD) device and bespoke on-chip intelligence, has shown that it could be a powerful technology in biosensing.

The research team has demonstrated detection of viral DNA binding events using fluoresence lifetime imaging at the very low target concentrations relevant in biosensing applications with acquisition times of less than 30 seconds.

DNA microarrays are important tools for biomolecular detection. Widely used for gene expression profiling, disease screening, mutation and forensic analysis, they also hold much promise for the future development of personalized drugs and point of care testing devices.

The team’s paper, published in Biomedical Optics Express, is titled “Fluorescence lifetime biosensing with DNA microarrays and a CMOS-SPAD imager.”

This work was funded by the EU's Sixth Framework program.

For more information, visit: www.megaframe.eu