Is it Malaria?

 The World Health Organization estimates that each year 300 million to 500 million cases of malaria occur and more than one million people die of malaria. A mosquito-borne disease caused by a parasite, malaria causes fever, chills, and flu-like illness. While there is currently no malaria vaccine approved for human use, the disease can be successfully treated if caught early. But some strains, such as the falciparum malaria strain, are particularly deadly.

Malaria occurs in over 100 countries and territories. More than 40 percent of the world's population is at risk. Source: Centers for Disease Control.

The surest way to detect malaria is to look for the malaria parasite in blood using a microscope. Unfortunately, access to electricity and medical expertise is a luxury for many in developing countries -- making it difficult to test early and often for malaria. A Duke-led interdisciplinary research team is trying to change this by developing an inexpensive, hand-held diagnostic for malaria using combined nanotechnology and genomic approaches.

To build the diagnostic, the team is attaching single strands of falciparum malaria DNA (the "probe") to optical sensors called microresonators. When the malaria parasite DNA strands (the "target") come into contact with the other half of the DNA strand on the sensor, the two complementary strands of DNA bind together. This binding is then detected by the sensor. This confirms the presence of falciparum malaria, and the team hopes it can ultimately provide information about the severity of the parasitic infection. To make this "chip scale" optical diagnostic portable, an optical laser source is needed, so the team has integrated a thin film laser directly onto silicon. To extract the DNA from the host's blood sample, the team is incorporating Richard Fair's microfluidics technology with the optical sensing system to create a ‘lab on a chip’ capable of taking blood from the patient and extracting, storing and moving DNA to the malaria detector.

The team has taken major steps toward chip scale integrated optical sensing diagnostic systems. The researchers’ surface customized microresonator sensors also have been demonstrated for chemical sensing, and have been integrated with optical waveguides (the "wires" that connect optical devices), and with photodetectors, all integrated onto silicon. The team has also demonstrated the integration of optical photodetection sensors with microfluidics systems. The research team includes electrical engineering Professors Nan Jokerst and Richard Fair, and Professor Debra Schwinn, now at the University of Washington.

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