June 15, 2018 (Vol. 38, No. 12)
Intense, Cool, and Long-Lived, UV LEDs Outshine UV Lamps, May Brighten Imaging Applications
Biomolecular contaminants dislike the spotlight, especially if it’s an ultraviolet (UV) spotlight. So, biomolecular contaminants must really hate the intense glare from decontamination systems that use UV light-emitting diodes (LEDs). One of these systems recently demonstrated that it can irreversibly inactivate RNase A—a pervasive contaminant in RNA sequencing and analysis labs.
Decontamination systems are hardly the only systems taking advantage of UV LED technology. By incorporating UV LED technology, chromatography/spectroscopy instruments are sharpening their detection capabilities, and sterilization systems are boosting their germicidal powers.
All these UV LED systems are available from Phoseon Technology, a company that has a strong background in solid-state semiconductor devices. Not long ago, Phoseon’s UV LEDs were confined to industrial curing operations. Now these UV LEDs are penetrating the life sciences, replacing relatively inefficient UV lamps and eliminating the need for harsh chemicals and long-term heat treatments. The company’s UV LEDs are even encouraging UV visionaries to anticipate more ambitious applications.
UV light in the UV-C frequency band, or “deep UV,” has always had the ability to induce fluorescence in biological material. But now that UV-C light can be wielded so much more effectively thanks to UV LED technology, once impractical applications are looking more realistic. For example, label-free fluorescence imaging, which would involve the excitation, detection, and possibly modification of molecules in tissues, is a near-term possibility in life sciences research. Diagnostic applications, too, are attractive possibilities, although they will take a little longer to realize.
A Bright Idea
Back in 2002, Phoseon started supplying UV LEDs that were optimized for industrial curing the cross-linking of polymer chains in adhesives and coatings. Then Phoseon decided to use its core technology to bring the power, stability, and control that set it apart in the industrial application to life sciences. The apparent foray into the life sciences, which officially began in 2017, was actually the culmination of preparatory and analytical work that stretched back to 2011.
Although industrial curing and the life sciences are very different, they both stand to benefit from progress in UV technology. Traditional UV technologies rely on xenon, halogen, mercury, or deuterium light sources. Those sources are relatively slow for decontamination and generate excessive heat.
“The UV lamps spark, and their output degrades over time,” says Chad Taggard, vice president and general manager of Phoseon’s life sciences division. “They also require high voltage.”
Many of the limitations of UV lamps can be overcome by UV LEDs, which are built on solid-state electronics and provide long-term consistency. “Intensity is the same from minute to minute, and from year to year,” notes Jay Pasquantonio, Phoseon’s strategy director. “It’s the same years later as it was on the first day. That’s important when you think about repeatability of process. We can provide more power in terms of UV intensity than anyone else, along with control and stability.”
Specifically, he says, Phoseon’s solid-state Semiconductor Light Matrix (SLM™) technology offers:
- Inactivation of molecules (including enzymes) and microorganisms that previously could be inactivated only by chemicals or high heat.
- Lower operating temperatures (up to 40°C vs. the 200°C of competing technologies).
- Instant start-up.
- A lifespan greater than 10,000 hours.
“UV LED disinfection is much faster than other approaches,” Pasquantonio asserts, pointing out that some items can be disinfected within a few minutes versus the 30 or more the same disinfection would take with other technologies. “If we can make the lab workflow more productive, that’s a win for our customers.”
Additionally, tunable wavelengths enhance capabilities. For instance, the Phoseon’s KeyView solid-state detectors for chromatography cover wavelengths of 210 to 800 nm, while new, deep UV technologies enable wavelengths of 215 nm and 220 nm to be used for protein and elemental analysis.
Innovating at UV Speed
Phoseon has developed a culture of continuous innovation. The company encourages its scientists, engineers, and managers to embrace unrelenting change, and to anticipate customers’ needs for better and faster products.
“We tend to be faster than our customers,” Taggard observes. “We have a disruptive technology, and we move quickly to deliver solutions into the market. We want to go faster and faster.”
Phoseon, impatient with the market’s seeming “paralysis by analysis,” decided to launch its KeyPro decontamination system last March, well ahead of schedule. (KeyPro enables RNA researchers and lab managers to decontaminate equipment after adding reagents and just before adding sample.)
“Frankly, we typically move quicker than internal development teams,” Taggard declares. “That means we can be more than a supplier. We can be an extension of a customer’s R&D team. When a customer embraces that model, we can help them get a product to market faster. With KeyPro, we knew we could finish the project quickly and make it available to both companies and end users, so we said, ‘Let’s do it!’”
It’s Phoseon Inside
Although the KeyPro and a handful of other solutions are designed for end users, most Phoseon light sources are sold as subsystems to OEMs throughout the world. “Development is a two-pronged approach,” states Taggard. The company’s engineers and scientists are focused on exploring the physical, chemical, and biological interactions of light, and are wholly focused on LEDs. The goal is to continuously exceed preconceived limits of power, stability, sensitivity, and miniaturization, and to enhance the utility of the UV LED as a light source.
When Phoseon works with a client, Phoseon staff members work closely with their client-based counterparts. “We synchronize our system with the OEM’s system, run experiments to provide efficacy data, and have our engineers work closely with the OEM’s engineers,” Taggard explains. Later, Phoseon ensures that it has the information that the OEM’s marketing team will need.
Phoseon also gets input from end users. “There are a lot of things a UV LED can do,” Taggard remarks. “It becomes a flywheel of what’s possible” as customers become interested in expanding applications for a solution, and then continue to do more.
An example of an expanding UV LED application is sterilization. In the United States, most surgical tools are disposable, but in Europe, single-use instruments are discouraged. When instruments are reused, reprocessing technologies need to be thorough without impairing instrument function. Ultraviolet disinfection is a reprocessing technology that delivers a shorter turnaround time than chemical and heat methods can achieve.
UV-C technology is another example. Besides being effective at disinfection, UV-C can detect and modify biological molecules. This autofluorescence capability makes it useful in highly specialized imaging. Eventually, it may be used for bedside diagnostics to identify disease states.
“Our goals are pretty simple,” Taggard says. “We’re growing very fast, and we want that to continue.” The greatest challenge in that regard, as with any disruptive technology, is overcoming market inertia. While potential customers and their end users acknowledge the benefits of this approach to disinfection, sterilization, decontamination, and chromatography, it takes time for OEMs to incorporate UV LED technology into their products. Eventually, that challenge will expand to diagnostics.