Key Points
- Handheld Raman instruments are gaining utility in low-resource healthcare settings for on-site diagnostics, counterfeit drug detection, and forensic applications. They offer real-time analysis without needing central labs, though legal acceptance requires thorough validation.
- The SERRS-enabled immunoassay system is adaptable to a broad range of biomarkers and sample types, with plans for multiplexed tests targeting diseases like TB and pancreatic cancer. This adaptability could revolutionize point-of-care diagnostics.
- The global diagnostic community, including efforts using SERRS/SERS, is working toward delivering rapid, reliable point-of-care tests within 100 days of outbreak identification. This is especially critical in TB-endemic LMICs, where affordable, accurate tests could save millions. Emerging materials, nanotechnology, and AI are poised to further transform this landscape.
This is the final part of our interview with Marc Porter, Distinguished Professor in Chemical Engineering at the University of Utah and the recipient of the 2025 Charles Mann Award, presented to an individual who has demonstrated advancement(s) in the field of applied Raman spectroscopy.
Here, discussing his recent paper on the subject (1), Porter discusses how, with portable Raman spectrometers entering decentralized healthcare, even the most remote settings can benefit from instant analysis—slashing turnaround times and costs while boosting patient care. This innovation extends to surface-enhanced resonance Raman spectroscopy (SERRS)-based immunoassays: highly flexible, multiplexable, and ready for a range of biomarkers and pathogens.
The Charles Mann Award will be presented at SciX 2025, taking place from October 5 to 10 at the Northern Kentucky Convention Center in Covington, Kentucky. Spectroscopy spoke to Porter about this study and the abovementioned article as part of our continuing interview series with SciX award winners.
How do you envision the role of handheld Raman instruments in decentralized or low-resource healthcare environments?
Handheld Raman spectrometers are slowly gaining traction as problem-solving tools in decentralized and low-resource healthcare settings based on their ability to provide on-the-spot. This capability lowers the need for samples to be sent to a central laboratory for analysis, which can be time-consuming and cost prohibitive. These portable analyzers can also be used in countering the distribution of counterfeit medications by quickly verifying the authenticity of a medication through comparisons to spectral libraries, and to identify if a white powder sample is or is not a street drug. This capability can also be used to aid in criminal investigations through the analysis of samples of gunshot residues and soon, to identify security features to confirm whether currency and important documents are legitimate or not. Meeting many of these needs will, nonetheless, will require an extensive series of validation studies certification for use in legal proceeding. Courts have, in fact, already accepted Raman spectroscopy as a source for reliable and prosecutable data.
What other diseases or biomarkers do you believe could benefit most from this SERRS-based approach?
A SERRS-based approach to sample readout, which, coupled with the layout of our immunoassay platform, is, in NIH parlance, highly extensible. An extensible immunoassay is one that can be modified or expanded to accommodate a wider range of analytes or sample types. It can also be reconfigured to operate in an automated multiplex modality for the concurrent detection of multiple biomarkers or be adapted for use with different sample matrices (for example, serum, plasma, urine, and cell lysates) without a complete test redesign. Changing the target biomarker can be achieved by identifying antibodies that can be used in the capture and labeling steps. The same antibody can be used in the capture and labeling steps when there are multiples of same epitope readily accessible on the antigen, whereas different antibodies are required when this is not the case. We believe these platforms will play an important role in the future of health care diagnostics and can be applied to a large swath of low and high molecular weight biomarkers, toxins, viruses, and bacteria. We plan to continue pursuit of a point of care (POC) test for TB using ManLAM as the biomarker, and multiplexed biomarker panel for pancreas cancer.
Let me add one more item to my response: What can we do to prepare for “Disease X? The Covid-19 pandemic taught the work several devastating lessons caused in large part by the glaring exposure of our inability to quickly launch life-saving responses to the outbreak. This wis perhaps best underscored by the many challenges faced during the development and rollout of diagnostic tests against the pathogen. The Group of Seven (G7), which is an informal bloc of industrialized democracies—the United States, Canada, France, Germany, Italy, Japan, and the United Kingdom (UK)—that meets annually to discuss international security issues, has pressed for innovations to ensure the delivery of reliable POC assays within 100 days of identifying “Disease X.” I believe that the diagnostics testing innovations under development by the interdisciplinary community aggregating around SERS and SERRS technologies has a pivotal role to play in tacking this “must be solved” challenge.
In what ways do you see this technology influencing global health outcomes, particularly in TB-endemic regions?
By way of background, breakthroughs in tuberculosis (TB) diagnostics remain a vital global health priority. The World Health Organization (WHO) estimates that there were 10.8M new cases of TB in 2023 and 1.09.Massociated deaths. More than >99% of this ongoing mortality occurred in low- and middle-income countries (LMICs) and is strongly linked to the fact that ~3M newly infected TB victims go undiagnosed each year from the lack of an accurate and affordable PON test. The irony is that TB can be cured if detected early, which further underscores the value of developing a field-deployable, accurate, low-cost TB test.
As is evident, POC tests for TB have the potential to significantly improve diagnosis and treatment, aid in transmission reductions, and improve patient outcomes. POC tests that can provide rapid and accurate results will accelerate early treatment rates, particularly in LIMCs. As of today, POC testing relies largely on genetics tests such like the GeneXpert MTB/RIF assay, which has a turn-around time of few hours. The GeneXpert uses real-time PCR to amplify and identify individuals infected with TB and detects genetic mutation indicative of multidrug-resistant TB. Nonetheless, health care organization like the WHO consider the cost per test with the GeneXpert ($15-25) presents an accessibility barrier in LIMCs. Our goal, which is beginning to more reachable per ongoing discussions with a major player in global health testing, is to provide an accurate, but low-cost, POC tests anyone who needs it.
What role do you see emerging materials or nanotechnologies playing in future evolutions of this platform?
It is without question that the daily breakthroughs in nanotechnology and material science signal that game changes in immunoassay development by opening new pathways to enhanced levels of sensitivity, specificity, and speed and by enabling POC testing and quick, and possibly real-time monitoring. The rate of change in this arena is almost breathtaking. Graphene materials are opening new routes to realized rapid and ultrasensitive analysis technologies, biomimetic membranes have begun to garner attention as an intriguing material to couple with surface plasmon resonance measurements, vertical flow assays are beginning to redefine the speed and quantitative capabilities of POC tests, and microfluidics now can carry out complex sample handing and preparation processes.
There is also a new elephant in the room: artificial intelligence or AI for short. Part of the AI arena is applying algorithms predict the design of new and improved molecular recognition elements that promise to move the selectivity of functional materials to unprecedented levels of performance. Look out. Health care diagnostics is poised for a revolution.
What are your thoughts on receiving the Mann Award?
Some experiences are hard to put into words. Learning I had been selected as the recipient of the Charles Mann Award for Applied Raman Spectroscopy was one of them. This honor reflects not just my own efforts, but the creativity, imagination, and dedication of the incredibly collaborative research team I’ve had the privilege to work with throughout my career. Our work brings together deep fundamental insights across chemical, physical, and biological systems to help bridge the gap between R&D innovation and real-world healthcare diagnostics. This award belongs to every past and present member of my research group. I’m profoundly proud of what we’ve built together.
References
1. Owens, N. A.; Pinter, A.; Porter, M. D. Surface-Enhanced Resonance Raman Scattering for the Sensitive Detection of a Tuberculosis Biomarker in Human Serum. J. Raman Spec. 2019, 50 (1), 15-25. DOI: 10.1002/jrs.5500
