Despite the low power consumption, UVC LEDs deliver higher light output in the UV wavelengths (Figure 3). As the emission
spectrum is proportional to the excitation spectrum, this higher
light output means stronger fluorescent signals. Thus, sensitivity
and accuracy are enhanced with UVC LEDs, even while consuming less power.
Lower power consumption may enable battery usage and
smaller footprint. Unlike the broad, complex spectra of traditional
UV lamps, LEDs have simple spectra—a single peak with a narrow
spectral bandwidth. Consequently, UVC LEDs can be used without filters, further simplifying the system to reduce size and cost.
Newly available high performance UVC LEDs have lifetimes of
3,000 – 8,000 hours depending on application conditions (Figure
4). The longer the life of the light source, the more measurements
that can be taken without the additional cost of replacement and
maintenance. As a result, optical detection with UVC LEDs is a
less expensive, simpler, and robust proposition compared to using
traditional UV lamps. Consequently, high performance LEDs,
especially at UVC wavelengths, can make optical detection at the
point-of-care level practical.
This exciting development of high light output UVC LEDs
allows the transformation of lab-on-chip products into clinically
useful point-of-care products. In the future, we can expect that
these solid-state light sources will be directly integrated into the
lab-on-chip device to transform the speed, accuracy, and delivery
of medical care. MDT
Figure 3: Irradiance comparison of UVC LED and Xenon Flash Lamp.
Note the difference in irradiance at the specific wavelength despite
the contrast in input power.
Figure 4: Comparison of UV light source typical lifetime.