Microfluidic biosensor detects pathogens

A reusable microfluidic biosensor has been developed by scientists in the US. 

The biosensor module is based on fluorescence detection and can quickly detect pathogenic organisms.  

Antje Baeumner at Cornell University, working with technology company Innovative Biotechnologies International, 
said their biosensor is easy to make, easy to run and very versatile. 

The biosensor’s operation is based on DNA/RNA hybridisation and liposome signal amplification. Target RNA is detected by a DNA probe coupled to fluorescent dye-entrapping liposomes.  

Magnetic particles capture this complex via another type of DNA probe and fluorescence microscopy detects the complex. The signal is enhanced an additional six times by lysis of the liposomes in the microchannel. 

The magnetic particles are an important part of the analysis procedure. A permanent magnet placed outside the microchannel allows the particles to be moved around. This enables the complex-forming paramagnetic particles to be collected, washed and removed with ease. 

The biosensor is one module in a bioanalytical micro total analysis system being developed for fast, reliable pathogen detection. The modules integrate to form a microsystem that will combine sample preparation and detection steps on a single chip. 

Future challenges lie in the complex nature of sample collection and the sensitivity and specificity of detection needed. Making devices to meet these challenges, by detecting within the right timescale, and which are truly portable, will ’require much more invention and development on the microfluidic level’, said Baeumner. 
Katherine Davies