Smartphone Accessory Detects AIDS-Linked Cancer
New plug-in sensor could be used for in-the-field diagnosis of Kaposi’s sarcoma (June 4)
Cornell University engineers have created a new smartphone-based system, consisting of a plug-in optical accessory and disposable microfluidic chips, for in-the-field detection of the herpes virus that causes Kaposi’s sarcoma.
“The accessory provides an ultraportable way to determine whether or not viral DNA is present in a sample,” says mechanical engineer David Erickson, who developed the technique along with his graduate student, biomedical engineer Matthew Mancuso. The technique could also be adapted for use in detecting a range of other conditions, from Escherichia coli infections to hepatitis.
Mancuso will describe the work at the Conference on Lasers and Electro Optics (CLEO: 2013), to be held June 9–14 in San Jose, California.
Unlike other methods that use smartphones for diagnostic testing, the new system is chemically based and does not use the phone’s built-in camera. Instead, gold nanoparticles are combined (or “conjugated”) with short DNA snippets that bind to Kaposi’s DNA sequences, and a solution with the combined particles is added to a microfluidic chip. In the presence of viral DNA, the particles clump together, which affects the transmission of light through the solution.
This causes a color change that can be measured with an optical sensor connected to a smartphone via a micro-USB port. When little or no Kaposi’s virus DNA is present, the nanoparticle solution is a bright red; at higher concentrations, the solution turns a duller purple, providing a quick method to quantify the amount of Kaposi’s DNA.
Erickson and Mancuso are collaborating with experts on Kaposi’s sarcoma at New York City’s Weill Cornell Medical College to create a portable system for collecting, testing, and diagnosing samples, which could be available for use in the developing world by next year.
Detecting Kaposi’s sarcoma isn’t the only goal, Mancuso says. “Nanoparticle assays similar to the one used in our work can target DNA from many different diseases,” such as methicillin-resistant Staphylococcus aureus (MRSA) and syphilis.
Source: Optical Society; June 4, 2013.