Researchers at Penn State have engineered a rapid testing technology for mpox, previously known as monkeypox. The mpox virus, which is transmitted through close contact with an infected person and that spread around the world last year, left healthcare staff grappling with a new problem. As the disease can be transmitted before symptoms arise, diagnosis is important in helping to stop the spread. However, conventional diagnostic approaches, such as PCR, are time consuming and require access to expensive lab equipment and qualified technicians. This latest technology uses gold nanoparticles that can bind viral nucleic acid. Once bound, the optical properties of the particles change, allowing the researchers to rapidly and conveniently detect the virus.
The mpox virus, previously considered endemic to parts of central and west Africa, rapidly spread around the world in 2022. While not as serious as its scarier cousin, smallpox, mpox is still an unpleasant disease, potentially leading to fever, a painful and itchy rash, exhaustion, and aches. Unfortunately, the disease is transmissible before symptoms arise, meaning that patient screening and rapid diagnosis are likely to play a big role in containing the virus. However, current diagnostic approaches typically require PCR analysis of patient samples, a cumbersome and time-intensive technique.
“We were interested in developing a sensitive detection method for pathogens generally, and also wanted to apply the concept to an emerging pathogen like mpox, because there is a real-world urgency for this rapid nucleic acid test,” said Dipanjan Pan, one of the lead developers of the new test. “There will be a significant impact on public health as a result of this technology.”
The new technology is based on plasmonics, whereby electrons in metal nanoparticles interact with light to create a signal that can be affected by nucleic acid binding. The nanoparticles in the current technology are made from gold, and they also interact with a thin layer of hafnium disulfide. The researchers functionalized the particles with strands of DNA that can specifically bind to a sequence in mpox nucleic acid. Once this binding occurs, the optical properties of the nanoparticles change, providing a clear signal that the sample contains mpox.
Images showing the nano-assembly mpox rapid test before (a) and after (e) the addition of mpox DNA. The red and green color encodes for gold nanoparticles and hafnium disulfide nanoplatelets respectively. The white arrows show dispersed gold nanoparticles and grouped gold nanoparticles. Credit: Courtesy of Dipanjan Pan. All Rights Reserved
“This technique does not require expensive equipment or skilled personnel, and it can be tailored for future mutations or emerging pathogens,” said Pan. “Scientists strive to provide the public with cutting-edge, advanced technologies that enable them to self-diagnose or get diagnosed at the point of care. This is what we have done.”
Study in journal Advanced Functional Materials: Nucleotide-Driven Molecular Sensing of Monkeypox Virus Through Hierarchical Self-Assembly of 2D Hafnium Disulfide Nanoplatelets and Gold Nanospheres
Via: Penn State