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Wiping a cuvette clean, running a blank, and then collecting data on a sample with a spectrophotometer reminds many scientists of days in biology lab classes. Spectrophotometers measure how much light of a particular wavelength is transmitted through a sample and/or how much is absorbed by the sample. The output can provide scientists with data about the sample, such as the activity, concentration, or structure of analyte. Some instruments measure the light that we can see—visible (VIS) light, which goes from red at about 700 nanometers to violet at 380 nanometers. The ultraviolet (UV)—from about 400 to 10 nm—can be detected with spectrophotometers designed to measure light across the UV/VIS range. Here, two experts in the field discuss advances in UV/VIS spectrophotometers.
Like many areas of technology, connectivity has changed the world of spectrophotometers. The Internet of Things (IoT) “in the lab is influencing how spectrophotometer technology is being developed,” says Marv Kaiser—global product manager, electrochemistry & spectroscopy at Cole-Parmer (Vernon Hills, IL). “It’s getting easier for scientists to control spectrophotometers via a Bluetooth-enabled smartphone, tablet, or computer or via WiFi.”
Let’s see why this matters, and discuss other advances in spectrophotometers, as well.
Keep it connected
Scientists can already make the jump to online spectrophotometry. “We specifically have the Jenway 74 and new Jenway 76 Series Visible and UV/Visible spectrophotometers with CPLive connectivity that is leading the market in this direction,” Kaiser explains. “Those working in a lab with our Jenway 74 and 76 Series spectrophotometers can safely and securely upload and archive data to the cloud, manage multiple devices at one time, share data with colleagues, and access unlimited data storage.”
For online spectrophotometry, the Jenway 74 (above) and new Jenway 76 (below) Series Visible and UV/VIS spectrophotometers come with CPLive connectivity. (Images courtesy of Cole-Parmer.)Even as Cole-Parmer gives these spectrophotometers so many capabilities, the devices get easier to operate. As Kaiser points out, “Intuitive user interfaces are making spectrophotometers easier to use, allowing manual-free operation.”
As more scientists than ever work together, sometimes from locations around the world, connectivity is key. Plus, being able to adjust a device, experiment, or lab to changing requirements also matters, and some IoT-capable spectrophotometers can do just that. With devices like the Jenway 74 and 76 Series spectrophotometers with CPLive connectivity, scientists can “easily scale their research, quickly add future devices, and intuitively manage multiple machines—all with a simple touch of a button,” says Kaiser.
All of these capabilities create more data, which the 74 and 76 Series have covered. “The 10G internal memory allows a user to save months to years’ worth of data securely without downloading,” Kaiser explains. For some labs, though, a year is too long to wait before backing up data. “For high-throughput labs, the CPLive app also allows the user to easily set up the continuous data-saving function with a simple mouse click, reducing the likelihood of missed/lost data,” Kaiser says.
Upping the analysis
More—that’s what labs always seem to need to do. That includes collecting more kinds of data and analyzing more samples, all as easily and quickly as possible. Sometimes, that requires using flexible tools.
When asked about the latest advance in UV/VIS spectrophotometers from BioTek Instruments (Winooski, VT), senior product marketing manager Lenore Buehrer points to the company’s Epoch 2 Microplate Spectrophotometer, which measures absorbance from 200 to 999 nm, selectable in 1-nm steps. “Controlled by Gen5 Software, its reading modes include endpoint, kinetics, well area scanning, and spectral scanning in 6- to 384-well microplates,” Buehrer explains. “The cuvette port provides convenient single-sample measurements, and BioTek’s unique Take3 Micro-Volume Plate allows up to 48, 2-microliter samples to be measured, which is ideal for direct nucleic acid and protein quantification, since sample dilution isn’t required.”
The Epoch 2 has Gen5 Data Analysis Software onboard. (Image courtesy of BioTek Instruments.)In short, a device that can read from cuvettes, microwell plates, and more is adaptable. “The Epoch 2 enables UV/VIS measurements for a wide range of throughput and assay requirements,” Buehrer notes. “Gen5 Software—available onboard via Epoch 2’s touchscreen or externally through computer control—automates pathlength correction for microplate measurements and includes easy preprogrammed protocols for conventional and microvolume analysis.”
The Epoch 2 has a port for standard 1-cm cuvette measurements (Image courtesy of BioTek Instruments.)Market mentions
Beyond the devices already noted, many more can be considered. To explore other options, click here.
Some manufacturers create entire families of UV/VIS spectrophotometers. Take Agilent (Santa Clara, CA), for example. This company’s Cary family of UV/VIS spectrophotometers provides many options. For instance, the Cary 300 can be used in single, dual, or dual-single beam optical modes. Models in this line can also offer wide ranges of wavelength detection. For instance, the Cary 50 and 400 read 190–1100 and 175–900 nm wavelength light, respectively.
Cecil Instruments (Cambridge, U.K.) also offers many options in the UV/VIS arena. For example, its AquaQuest UV/VIS Spectrophotometer covers 190–1100 nm with 0.1-nm resolution, using a Littrow monochromator. This is just one of a variety of platforms offered by the company.
Although many of us remember using spectrophotometers during introductory lab classes, research scientists use UV/VIS devices in various research projects. As an example, one team of scientists used a UV/VIS spectrophotometer to analyze chitosan nanoparticles (T-CSNPs), which were synthesized with an enzyme from a fungus, Trichoderma harzianum.1 In this study, the scientists wanted to make the nanoparticles, and then analyze them for biocompatibility, antioxidant, and bactericidal properties. The team confirmed the synthesis of the nanoparticles with absorbance at 280 nm.
This technology can be used beyond applications in the life sciences. One team of scientists used UV/VIS spectrophotometry when studying how the environment degrades optical silicone.2 As they noted: “Environmental degradation of silicone free form, used as secondary optics in light emitting diode (LED) lighting lamps and luminaires or any other applications requiring high-quality optics being used, has negative implications for the optical performance.” The scientists exposed silicone plates to salt baths or swimming pool water, plus light and temperature—testing some samples for as long as four months. After the exposure, the scientists examined the silicone plates with various techniques, including UV/VIS spectrophotometry. Perhaps not surprisingly, they found: “Increasing exposure time in the salt bath at that high temperature is associated with a significant deterioration of both optical (i.e., light transmission and relative radiant power value) and mechanical properties of silicone samples.” What might be a surprise is that the “silicone plates showed a great degree of stability against light exposure (UV at 360 nm and blue light at 450 nm).”
So, we never know what might be found with a UV/VIS spectrophotometer. The good news is that a range of products make it easy to apply this technology to many questions. Even better, we see once more how we can use those techniques that we learned in the beginning of a scientific career.
References
- Saravanakumar, K.; Chelliah, R. et al. Fungal enzyme-mediated synthesis of chitosan nanoparticles and its biocompatibility, antioxidant and bactericidal properties. Int. J. Biolog. Macromolecules 2018, 118(Pt. B):1542–9.
- Yazdan, M.M.; van Driel, W. et al. Study on the degradation of optical silicone exposed to harsh environments. Materials 2018, 11(8), pii: E1305.
Mike May is a freelance writer and editor living in Texas. He can be reached at [email protected]