Early diagnosis of infectious diseases can lead to accurate treatments and can prevent transmission and long-term complications. But to detect and identify an infectious disease is not easy. Disease-causing pathogens are normally present in low concentrations, requiring extremely sensitive devices for detection. And because many infectious diseases have similar early-stage symptoms, it can be difficult to differentiate among them.
Researchers at the University of California, Santa Cruz and Brigham Young University have developed a promising new approach that may provide a solution to these problems. The team utilized a unique design and configuration to create a device capable of both spatial and spectral multiplex analysis, allowing simultaneous detection of multiple pathogens and samples. This is beneficial because standard diagnostic test panels contain multiple pathogens, and the abililty to scale up is important for cost and efficiency.
Integral to the approach is an optofluidic chip with a solid-core waveguide that intersects three separate liquid-core waveguides, and a coupler that combines signals from each of these liquid-core waveguide channels. When samples are placed in the channels and excited with multiple optical wavelengths, a characteristic excitation spot pattern emerges. The patterns can then be analyzed to identify the sample.
“The main advance is the system’s enhanced multiplexing capability,” says Baskin School of Engineering professor Holger Schmidt, an expert in optofluidic devices. “By using multiple channels and multiple wavelengths of excitation, we can reach clinically relevant numbers without changing the analysis method or making the optofluidic chip much more complex to build.” The new optical design was translated into functional silicon chips by Professor Aaron Hawkin’s group at BYU.
Using multiple fluidic channels simultaneously has several advantages. First, tests can be run simultaneously on samples from three different patients, thus speeding up the screening and detection process in large groups of individuals. Second, different virus types can be detected simultaneously within a single sample. Third, a single sample can be split into three sections and analyzed three times faster. This versatility in sample analysis means the device can be deployed in various ways, depending on clinical need.
The new method provides a means for differentiating among several pathogens and opens the door to commercialization of this optofluidic technology for medical diagnostics. In a paper published in Scientific Reports, the researchers -- which included UC Santa Cruz Electrical Engineering postdoctoral researcher Aadhar Jain and graduate student Alexandra Stambaugh -- demonstrated simultaneous detection and identification of six different viruses from a standard influenza panel.
Read the full article in nature.com Scientific Reports.