A research team led by Dr. Paul Wiseman of the Departments of Physics and Chemistry at McGill University has developed a radically new technique that uses lasers and non-linear optical effects to detect malaria infection in human blood, according to a study published in the Biophysical Journal. The researchers say the new technique holds the promise of simpler, faster and far less labour-intensive detection of the malaria parasite in blood samples.
Malaria is a vector-borne infectious disease spread by parasites of the genus Plasmodium. Most common in tropical and subtropical regions, it is a global scourge with 350 to 500 million new cases – and one to three million fatalities – reported annually. Most of the fatalities are concentrated in sub-Saharan Africa, where the resources and trained personnel currently required to accurately diagnose the disease are spread the thinnest.
Current detection techniques require trained technicians to stain slides, look for the parasite’s DNA signature under the microscope, and then manually count all the visible infected cells, a labourious process dependent on the skill and availability of trained analysts. By contrast, the proposed new technique relies on a known optical effect called third harmonic generation (THG), which causes hemozoin – a crystalline substance secreted by the parasite – to glow blue when irradiated by an infrared laser.
“People who are familiar with music know about acoustic harmonics,” said Dr. Wiseman. "You have a fundamental sound frequency and then multiples of that frequency. Non-linear optical effects are similar: if you shine an intense laser beam of a specific frequency on certain types of materials, you generate multiples of the frequency. Hemozoin has a huge, non-linear optical response for the third harmonic, which causes the blue glow."
Dr. Wiseman and his colleagues now hope to adapt well-established existing technologies like fibre-optic communications lasers and fluorescent cell sorters to quickly move the technique out of the laboratory and into the field.
"We’re imagining a self-contained unit that could be used in clinics in endemic countries," said Dr. Wiseman. "The operator could inject the cell sample directly into the device, and then it would come up with a count of the total number of existing infected cells without manual intervention."
Source: McGill University
Related stories:
Controlling light with sound: new liquid camera lens as simple as water and vibration
New miniature image-capturing technology powered by water, sound, and surface tension could lead to smarter and lighter cameras in everything from cell phones and automobiles to autonomous robots and miniature spy planes.
Scientists create first dense gas of ultracold 'polar' molecules
Scientists at JILA, a joint institute of the National Institute of Standards and Technology (NIST)and the University of Colorado at Boulder, have applied their expertise in ultracold atoms and lasers to produce the first high-density gas of ultracold molecules—two different atoms bonded together—that are both stable and capable of strong interactions.
Shimmering ferroelectric domains
Ferroelectric materials are named after ferromagnetic ones because they behave in a similar way. The main difference: these materials are not magnetic, but permanently electrically polarized. They have great importance for data storage technology and novel piezoelectric devices. Dresden scientists were able to produce microscopic images of ferroelectric domains - tiny regions of a ferroelectric material -, where the electric polarization points into different directions. These results were published in the journal
Physical Review Letters recently.
New nanotech research to enhance future digital imaging
A team of researchers from Northeastern’s Electronic Materials Research Institute has published research that has resulted in a new breakthrough in the field of nanophotonics, the study of light at the nanoscale level.
Researchers report finer lines for microchips: Advance could lead to next-generation computer chips, solar cells
MIT researchers have achieved a significant advance in nanoscale lithographic technology, used in the manufacture of computer chips and other electronic devices, to make finer patterns of lines over larger areas than have been possible with other methods.
A better image for plastic solar cells
A new way to help technologists develop efficient and inexpensive plastic electronic devices, such as plastic solar cells and a new type of transistor was showcased by physicist Andrea Liscio, who is supported by the European Science Foundation, at the EMRS (European Material Research Society) Spring Meeting held in Strasbourg, France at the end of May.
Visualizing atomic-scale acoustic wavesin nanostructures
Acoustic waves play many everyday roles - from communication between people to ultrasound imaging. Now the highest frequency acoustic waves in materials, with nearly atomic-scale wavelengths, promise to be useful probes of nanostructures such as LED lights. However, detecting them isn't so easy.
New technology may help Olympic sailing
A team of researchers at the Ocean University of China has developed and tested a mobile lidar (light detection and ranging) station that can accurately measure wind speed and direction over large areas in real time -- an application useful for aviation safety, weather forecasting and sports.