Researchers at US health group Mass General Brigham have developed a novel diagnostic tool which uses bioluminescence to more accurately identify viruses including SARS-CoV-2, HIV, HBV, and HCV in patient samples.
LUCAS (Luminescence CAscade-based Sensor) is a rapid, portable, highly sensitive diagnostic tool for processing complex biological samples. Compared to its diagnostic predecessors, LUCAS creates 500-fold stronger and eight-fold longer-lasting bioluminescence signals, overcoming longstanding challenges faced by point-of-care diagnostics. The new advance is detailed in a study published in Nature Biomedical Engineering.
“Developing effective diagnostics is incredibly challenging, especially when you think about the size of infectious disease particles and the complicated biological fluids we’re attempting to identify them in. Finding an HIV particle in a human blood sample is like finding an ice cube in a jelly-filled Olympic swimming pool while blindfolded,” said senior author Hadi Shafiee, PhD, a faculty member in the Division of Engineering in Medicine and Renal Division of Medicine at Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system. “With its novel enzyme cascade approach, LUCAS marks a substantial leap forward for sensing viruses in these complex biological samples.”
Mass General Brigham is a not-for-profit, integrated health care system that engages in medical research, teaching, and patient care. It is the largest hospital-based research enterprise in the United States.
Point-of-care diagnostics are widely used for disease detection, treatment, and monitoring. Yet current diagnostics can fall short, with faults like inaccuracy and poor sensitivity. Bioluminescence has the potential to alleviate common shortcomings experienced by other methods, like background noise, false positives, photobleaching and phototoxicity.
Bioluminescence utilises the same natural enzyme that makes fireflies glow to light up biological samples for imaging. The enzyme, luciferase, is added to a sample to find and flag viral particles. Then, luciferin molecules are introduced to that sample, prompting a luciferase reaction that creates a burst of light. But this reaction produces a light signal that is both weak and short lived.
Shafiee and team developed a unique enzyme signal cascade to strengthen and prolong bioluminescence signals. They introduce another enzyme to the equation, called beta-galactosidase, that sticks to luciferin and releases it continuously, rather than allowing luciferin to float freely in the sample for one-and-done reactions. This extra step means more luciferin, more luciferase reactions, and more bioluminescence. In fact, this step enabled LUCAS to be 515 times more bioluminescent than non-LUCAS systems, and LUCAS signals maintained 96% strength after an hour.
To evaluate LUCAS’ efficacy, the team used 177 viral-spiked patient samples and 130 viral-spiked serum samples infected with either SARS-CoV-2, HIV, HBV, or HCV. SARS-CoV-2 patient samples were collected via nasopharyngeal swab, while HIV, HBV, and HCV samples were collected via blood draw. LUCAS provided diagnostic answers within 23 minutes and with an average accuracy across all pathogens of over 94%.
The researchers designed LUCAS to be both portable and easy to use so that it can be an option for high- and low-resource point-of-care environments. As a next step, the team will be testing LUCAS’ efficacy in other biological fluids and whether the method can identify more than one pathogen at once. Shafiee also notes that biomarker identification for many diseases, including Alzheimer’s, is a rapidly evolving space - so having a tool like LUCAS ready to go as new biomarkers emerge could prove impactful in years to come.
“We always want to detect infection and disease as early as possible, as that can make all the difference when it comes to care and long-term outcomes,” said first author Sungwan Kim, PhD, a postdoctoral researcher in Shafiee’s laboratory at the Brigham. “With our focus on developing diagnostic tools that are sensitive, accurate, and accessible, we want to make early detection easier than it has ever been and push personalised care into a new era.”
- Kim S, Cho G, Lee J, et al. Ultrasensitive and long-lasting bioluminescence immunoassay for point-of-care viral antigen detection. Nat Biomed Eng. 2025 May 30. doi: 10.1038/s41551-025-01405-9. Online ahead of print.