The new high performance ultraviolet LED has the same stability as the high-end deuterium lamp with a peak fluctuation of less than 0.005%. UV-C LEDs provide similar sensitivity while reducing the cost and size of the overall instrument for fixed-wavelength detection. In this way, when the manufacturer needs a single or several fixed wavelengths, it can help the end user to rationalize the use of laboratory area. In addition, unlike deuterium lamps, LEDs provide longer lifetime and are turned on immediately to ensure that the LED lifetime is not wasted in preheating. In addition, light from LEDs can be easily coupled by optical fibers, which is advantageous in applications requiring isolated flow pools. Manufacturers can choose UV-C LEDs as alternatives to fixed-wavelength detectors and build more cost-effective systems.

For fixed-wavelength HPLC systems, the biggest difference in cost usually comes from the cost of the initial configuration because it includes light sources and other ancillary equipment. The HPLC system using the LED detector requires power supply, photodiode and beam splitter. The total cost of the HPLC detector system with LED is about $750. In contrast, the HPLC system using deuterium light sources needs more expensive equipment to build. The necessary power is much more expensive and needs space to store the lamp. In addition, the deuterium lamp is a broad spectrum light source, emitting many wavelengths of light in the ultraviolet range. This requires the use of expensive filters and monochromator for fixed wavelength HPLC detection. Therefore, the typical system cost is expected to be close to US $4000. Figure 1 shows the design of a typical instrument using deuterium lamp (a) and UV-C LED (b).

Reduce the cost of DNA purity measurement

Another example of the use of UV-C LED next is DNA concentration and purity measurement. DNA extraction ensures the integrity of biological research and affects many areas, such as biotechnology, forensic medicine, genomic research and drugs. This includes the detection of genetic disorders, the generation of DNA fingerprints, and the generation of genetic engineering organisms.

In these applications, the key to improving productivity and reducing costs is the speed and accuracy of measurement. DNA and protein have absorption peaks at 260 nm and 280 nm, and the absorbance at these wavelengths determines the concentration of DNA and protein respectively, and the absorbance ratio determines the purity of DNA samples. Spectrometers for DNA concentration and purity measurements rely on xenon flash lamps, which provide instant on/off and allow rapid evaluation of high linearity measurements over a wide range of concentrations.

Although broad-spectrum ultraviolet lamps (such as xenon flashes) can produce sufficient light at multiple wavelengths (most of which are visible), only light of a specific wavelength can be used to measure a single parameter. Since DNA purity is determined by absorption measurements at 260 and 280 nm, other components, such as filters and reflectors, must be used to filter out unwanted wavelengths before the broad-spectrum lamp illuminates the sample. The xenon flash still needs high voltage and increases the protection of electronic equipment during lighting. These expensive electronic devices, together with other optical components, rapidly increase the overall cost of the instrument.