Integrating New Digital Microfluidics Platforms in Real-World Clinical Settings

Integrating surface-enhanced Raman spectroscopy (SERS) assays with digital microfluidics (DMF) can lead to new breakthroughs in analytical instrumentation. But how can these advancements be applied in clinical analysis?

A conversation with Sian Sloan-Dennison, a postdoctoral research associate at the University of Strathclyde, explored this question at length.^1–5 We share those insights below in this exclusive Q&A.

Would you be able to explain how integrating a SERS assay with a DMF platform helps improve the sensitivity, reproducibility, and throughput compared to traditional and other bulk solution approaches?

In terms of sensitivity, the DMF will enable the precise manipulation of these regulator droplets, so we have control on seeing how many hybridization events could occur by creating the incubation step and making it a lot more tailored to what we need. Increasing the amount of incubation or hybridization steps should increase the sensitivity. Also, SERS is very specific for how many nanoparticles are present, so overall, it is a much more sensitive technique than say fluorescence or chemiluminescence, usually used in terms of reproducibility. We're taking away that manual pipetting and shaking elements, so by taking in the droplets, we're very precise with how much that we are adding to our systems. We have precise steps for the incubation step, so we're taking away all that ambiguity that you can have with pipetting and errors that I could have made in a sample solution assay. By putting on the chip, we should have much more reproducible results between samples, and for throughput, the chip now currently can do four assays at once. So, we do three repeats and then do another concentration, or we can start to include internal standards to make sure that the assay is reproducible and that we can have faith in the results. Because we have that throughput to run in multiple assays at once, this hopefully could be a quite high-throughput assay that people could run in point-of-care settings. Operation of DMF and SERS will increase that sensitivity and hopefully give more robustness to your results.

How do you envision this platform being implemented in real-world clinical settings, particularly in emergency departments?

I think in an ideal scenario, you'd be taking a finger prick of blood and then applying it straight to our DMF platform. It's a little bit bigger than the lateral flow that we have usually used, so it might be in a central bay within the emergency department. It's got quite a small footprint, so if we can try and enclose everything and keep the laser safe to use so that it's not shining in the emergency departments, that’s where we could see it. I think just now instead of taking 20 mL of intravenous blood, you could take a finger prick of a sample, attach it to or apply it to the DMF, and then you would wait 10 min for the incubation step.

Can you talk about the current skill gaps that younger researchers can help address?

One thing you have to consider with the SERS assay you're building, or your random probe that you're designing, is where it is going to be used. Is it going to be an early diagnostics tool, or is it going to be for patients to use themselves? This can really dictate the path of your research. For example, if you're building a SERS assay and you're relying on all your reagents to be stored in the fridge, that sometimes isn't possible. Sometimes, you have to have your assay be stored at room temperature. So that may start making you think: how do I make this stable? I need to start thinking about the design so you don’t run into a situation where you have made a fantastic series assay, but it can never go anywhere, because you have to keep things in -80, where you just can't keep that -80 in the clinical ones.

Another big thing to consider is: how safe is your platform? There's lots of different hurdles that you have to overcome when building a Raman probe, so you have to know if it's going to be used in accident and emergency departments. That might mean using a low laser power, so if your assay needs that high laser power to be sensitive, you might want to reconsider trying to build a different sort of particle to give you that increase in signal to begin with. And I think finally, if you can get your hands on clinical samples as early as you can, that'd be really great for validating your assay, and I've done this myself.

We can make fantastic SERS assays and detect lots of clinically relevant biomarkers and buffers great, but as soon as you add a complex environment, you could lose the sensitivity and lose that binding that is vital for your test. By using that complex environment near the start of building that assay, it means that when you move on to clinical applications, you're already there, and you have faith that it's going to work straight away. These are the things that I've encountered as well in my work, so it'd be really good to tell our Ph.D. students as well that this is what we should be thinking of, and it's all really important to look at.

Do you have any tips or practical advice for young researchers that are in the process of trying to secure a postdoc position at a research university?

I think going to conferences like Spring SciX is a fantastic opportunity for networking and for maybe meeting someone who'd be your future postdoc advisor. I think it's always good to try and connect with them through what they spoke about if you're following the research as well and just try and grab them for a five-minute conversation to discuss their work. Then, when you go to email them, you have that connection, and this is actually how I got my first postdoc.

I will also say that make sure a postdoc is the career that you want as well because it can be short-term contracts, and sometimes it involves moving away from your support network. So, when you do get that position if you have moved away, making sure that you have a work–life balance, such as having hobbies outside of work that are vital to keeping you grounded while you are in the laboratory. And then, once you are a postdoc, obviously the work you're doing will be really important, but get involved in what the students are doing as well. Being a Ph.D., you sometimes aren't exposed to being a supervisor or having that mentor role, so I enjoyed seeing what the Ph.D. students are doing and interacting with them a lot more about their research. Doing this will probably help with future careers if you want to go into academia, but it's such good transferable skills to take into industry as well. So, I'd really recommend trying to see what the whole laboratory is doing, and at that case you end up learning more as well.

References

1. Sloan-Dennison, S.; Wetzel, W. Why Current Tests for Assessing Drug Induced Liver Injury Fall Short. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/why-current-tests-for-assessing-drug-induced-liver-injury-fall-short (accessed 2026-05-26).
2. Sloan-Dennison, S.; Wetzel, W. What were the Main Takeaways of the Spring SciX Conference? Spectroscopy. Available at: https://www.spectroscopyonline.com/view/what-were-the-main-takeaways-of-the-spring-scix-conference (accessed 2026-05-26).
3. Sloan-Dennison, S.; Wetzel, W. The Benefit of Integrating a SERS Assay with a Digital Microfluidics Platform. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/the-benefit-of-integrating-a-sers-assay-with-a-digital-microfluidics-platform (accessed 2026-05-26).
4. Sloan-Dennison, S.; Wetzel, W. The Current Skills Gaps in Biological and Clinical Analysis. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/the-current-skills-gaps-in-biological-and-clinical-analysis (accessed 2026-05-26).
5. Sloan-Dennison, S.; Wetzel, W. Securing a Postdoctoral Position at a Research University. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/securing-a-postdoctoral-position-at-a-research-university (accessed 2026-05-26).