Fluorescence Applications

In the world of winemaking, color is one of the first sensory experiences, setting the stage for the entire tasting journey. Yet, various winemaking practices and environmental factors can diminish the intensity and richness of a wine's color. This has led some winemakers to covertly enhance their wines with concentrates from intensely colored (Teinturier) grapes. Detecting these additions is challenging due to the complex pigment compositions in red wine grape varieties.

Water travels through the environment carrying dissolved organic matter (DOM), made up of various chemical compounds, which have entered the water column from many sources.

The Duetta was used to collect Excitation-Emission Matrices that distinguish different species of essential oils, as well as the same species by region of origin. A 50/50 mixture of lavender and eucalyptus demonstrated the ability of the approach to qualitatively identify an adulterant.

Verifying the quality of lavender essential oil is crucial to ensure it is safe for its intended use, and to ensure consumers aren’t being deceived into buying inferior products. Two samples of lavender essential oil with identical label claims of "Pure", one from a supplier that tests for quality and one that does not, were evaluated with A-TEEM spectroscopy and GC-MS.

Saffron is a target for adulteration due to its high price. Other compounds can be added, such as minerals, oils or synthetic colorants. The two in one Duetta spectrometer was used to rapidly acquire Excitation Emission spectra for different saffron samples from different suppliers.

In this application note, a method for accurately predicting the amounts of major constituents of kava root from spectroscopic absorbance and fluorescence measurements made with the HORIBA Aqualog® and the A-TEEM technique is presented.

We introduce A-TEEM™ spectroscopy as a new and fast way to analyze 45 specific quality parameters in wine. A-TEEM, a fluorescence spectroscopy technique, simultaneously acquires transmission, absorbance, and fluorescence Excitation Emission Matrices, overcoming the inner filter effect on the fly.

HORIBA’s Duetta, a CCD-based dual fluorescence/absorbance spectrometer is a very capable instrument for the determination of Chl A concentration by fluorescence due to its inherent sensitivity and ability to automatically correct for the inner filter effect (IFE), which ensures a very high dynamic range for such analysis. It also can be used to quantify the concentration of the standard stock solution by absorbance, thus eliminating a need for a dedicated UV-VIS spectrometer.

Global drinking water sources remain prone to carcinogenic petroleum product contaminations due to lack of detection capacity at or before treatment plant intake. The Aqualog A-TEEM method provides a reliable optical detection of these compounds at low quantities discriminating from the highly absorbing and fluorescent backgrounds of natural Dissolved Organic Matter (DOM) components.

The Fluorolog-QM fluorescence spectrometer with an integrating sphere option is an excellent choice for PLQY measurements in NIR. The K-Sphere is very convenient and easy to use, as it couples directly to the sample compartment optics and allows a use of external light sources, such as DPSS lasers, which can be attached to the front of the sample compartment. The sphere has holders for cuvettes, slides and powders that can be easily interchanged. The results demonstrate very good reproducibility and precision for NIR PLQY measurements spanning almost two orders of magnitude. Based on multiple measurements, the demonstrated PLQY standard deviations range from 1.3% for high QY value (77%) to 6.4% for the QY below 1%.

The Fluorolog-QM’s advanced modularity supports the characterization of electroluminescent materials across a broad time range, from nanoseconds to seconds, without the need for external devices.

This app note demonstrates that the A-TEEM molecular fingerprinting technique can easily distinguish between different components in mixtures that contain FF and other ingredients considered to be adulterants, including lignosulphonates, organic acids, molasses, and provides a quantitative evaluation of mixtures.

The new Fluorolog-QM spectrofluorometers, due to their modularity and advanced software and a universal interface, are an ideal choice for studying multiple aspects of upconversion. This technical note illustrates the use of Fluorolog-QM-75-21 for spectral and time-resolved characterization of these materials.

In the food industry, the compounds characterization is a critical step to ensure the quality of the products or to provide information to customers which can be sensitive to allergies. In this application note, we showed how optical spectroscopies and laser diffraction can help for food compounds characterization, especially on a specific product, i.e. milks.

The Aqualog A-TEEM spectrometer has the capacity to specifically identify and sensitively quantify key adulterants that are most commonly detected in Cranberry dietary supplements, including Pine Bark, Grape Seed and Peanut Skin extracts.

In this application note, we highlight the high sensitivity of the Duetta for measuring transferrin at very low concentrations. The Duetta spectrofluorometer combines both fluorescence and absorbance measurements simultaneously, thus providing key advantages for protein analysis. In parallel, we compare the fluorescence results obtained using the Duetta with absorbance results obtained with a dedicated low-volume, benchtop spectrophotometer.

Stability and aggregation of insulin are studied using simultaneous fluorescence excitation emission matrices (EEMs) and UV-Vis absorbance spectroscopy [1]. Insulin is a protein-hormone, produced by the pancreas and is necessary for basic metabolic processes. The different types of commercial insulin therapeutics generally fall into two categories: short-acting and long-acting insulin. The difference between some short-acting and long-acting insulin is, in some cases, only one to three residues in the protein sequence.

Aqualog®, an analytical instrument based on the simultaneous measurement of Absorbance, Transmittance, Fluorescence Excitation and Emission Matrix (A-TEEM). A-TEEM fingerprints yield qualitative and quantitative composition of key flavor and color determinants in wine and spirits that are not discernible with simple Absorbance or Transmission data analysis.

With their ~20 % efficiency, hybrid perovskite solar cells are the new promising candidate for next generation photovoltaics. Thanks to the wide HORIBA Scientific portfolio, different techniques can be used to gain in depth knowledge on the optoelectronic properties and mechanisms of this class of materials. In this application note we decided to use spectroscopic ellipsometry, steady-state and time-resolved fluorescence and Glow Discharge Optical Emission Spectroscopy to investigate the properties of CH3NH3PbI3 thin films deposited on a spin-coated PEDOT:PSS. The impact of the exposure to air was addressed.

Duetta is an analytical instrument capable of recording both the fluorescence and the absorbance of a sample. Absorbance data provides concentration-dependant information on non-fluorescent compounds. Through its user-friendly software, Duetta allows different measurements related to biomolecules like DNA, RNA and proteins including protein concentration, DNA/RNA purity, finding the concentration of an unknown sample based on a standard-based calibration curve, Pass/Fail testing and all standard fluorescence and absorbance related measurements. All these functionalities are possible through dedicated applications in EzSpec™ software for Duetta.

Monitoring of Sulfur in petroleum products is an important topic in the current environmental protection context. Indeed, during combustion, Sulfur will cause acid rains and particles emissions that induce environmental and health problems. If industries and vehicles emissions have been the main target of Sulfur emission control since few tens of year, the new target is the maritime navigation. In this domain, now, the level of Sulfur is regulated by the MARPOL (International convention) Annex VI. For this specific regulation, the technique and measuring range of our SLFA series is perfectly suitable to allow the fast and accurate determination of Sulfur in Marine oil. Our compact SLFA-60 can be used on board and the SLFA-6800, with its autosampler (eight positions), will enhance the productivity of the control laboratories.

The study of singlet oxygen (1O2) is of interest, principally, as it is a highly reactive species. It can be produced by photosensitisation, usually of a molecule such as a dye or porphyrin. Thus, by the appropriate selection of sensitiser, the presence of oxygen and light, 1O2 can be selectively generated. From a biological aspect it has the ability to damage and destroy cells, which has lead to interest in its use as an anticancer agent in photodynamic therapy (PDT).

HORIBA’s Aqualog is uniquely equipped with patented simultaneous Absorbance spectral and fluorescence excitation-emission matrix (EEM) technology which provides rapid access to a wide range of parameters important to commercial wine processing and quality characterization.

The use of metal surfaces in conjunction with fluorescence molecules employing a plasmon effect, sometimes referred to as metal enhanced fluorescence, can be advantageous because of the possible enhancement of photophysical properties.

The use of security features, such as luminescent inks, has increased significantly in an attempt to prevent fraud and counterfeiting of materials and goods.

No need to sample—simply take your readings directly in place in locations such as reaction vessels Collecting samples during a continuous process can be tedious and even dangerous if hazardous materials are involved.

The use of time‐resolved fluorescence has expanded as the relative cost of instrumentation has decreased in recent years. One area where this is especially true is in the food industry, where time‐resolved fluorescence has been applied in the characterization of food stuffs as well as aspects related to food safety and degradation.

The resurgence of interest in the Mediterranean Diet and its associated health benefits have directed focus on the role that Extra Virgin Olive Oil plays. The increasing awareness is leading to increasing product demand, but also opportunities to compromise quality. Hence the need for rapid analytical methods to perform Quality Analysis of various product samples.

The new HORIBA Duetta fluorescence and absorbance spectrometer offers many unique benefits for molecular spectroscopy. It is primarily thought of as a spectrofluorometer that combines absorbance and fluorescence spectroscopy to correct the fluorescence fingerprint for concentration-related effects. Duetta can also be used as a precise absorbance spectrometer. This application note explores the use of Duetta for a common absorbance application, the Protein A280 application.

Certain fluorescent molecules, known as molecular rotors, can be employed to estimate the local (nanoscale) viscosity in microheterogeneous systems by measurement of their fluorescence lifetime. This can be advantageous over the usual fluorescence anisotropy method, as the measurement is simpler and faster to perform. This is demonstrated using the HORIBA Scientific TemPro fluorescence lifetime system to monitor the gelation of silica produced using the sol‐gel technique.

International terrorism, security concerns, and the remains of forgotten landmines throughout the world have increased interest in detection of explosive materials.

The Nanolog has a reputation as the premier instrument for the exploration of single-walled carbon nanotubes (SWCNTs).

Silica is currently one of the most important industrial materials, whose nanoparticles are formed via a sol-gel process.

Hybrid perovskite photovoltaics (PV) show promise because of their good efficiencies, which can be around 20%. Along with their PV characteristics, perovskite materials exhibit a high degree of radiative recombination.

HORIBA Jobin Yvon’s spectrofluorometers have many applications in nanophotonics research: single-walled carbon nanotubes (SWNTs), quantum dots (QDs), and organic light-emitting diodes (OLEDs). Quantum confinement affects nanomaterials’ photoluminescence: when the semiconducting nanoparticle is smaller than the bulk material’s Bohrexciton radius, the bandgap energy is inversely proportional to the nanoparticle size.

The brightly-colored coral reefs that make scuba-diving and snorkeling so enjoyable are essential to the survival of much underwater life. Not only do reefs offer a haven for smaller fish to hide from larger predators, but also some fish actually survive by eating the reefs themselves. Reefs offer protection to plants and animals from the ravages of waves and ocean currents. Thus, when the reefs die, so do many other living creatures.

This Application Note outlines three different kinds of spectroscopic tools being used for the characterization of sunscreens, and discusses the obtained results. These include Fluorescence spectroscopy for photoactivity, Particle Size analysis for composition and Raman microscopy for formulation investigation.

This technical note serves as a guideline to selecting the best solid state detector with the Fluorolog-QM modular research spectrofluorometer for a given series of photoluminescence experiments.

With the rise of protein production using mammalian cell culture, it has become increasingly important to control the quality of the cell culture media for use in production processes. Cell culture media are usually prepared as aqueous solutions and should provide everything a cell line needs for optimal cell growth as well as product yield and quality.

The phenomenon of upconversion is an optical process that takes in lower energy (longer wavelength) photons and emits higher energy (shorter wavelength) photons.

Glasses are essential materials with a multitude of uses and many forms. In the area of optoelectronics there is an interest to modify the glass composition to favor the incorporation of lanthanide elements.

Automobile-parts production can be paralyzed by a defective electrongalvanizing (EV) bath line.

Light incident on a leaf can be absorbed by chlorophyll to commence the photosynthetic cycle. Excess energy can be liberated as heat or by emission of fluorescence and this can be used to assess the efficiency of the photosynthetic process.

Biological tissues contain chromophores that absorb light, as well as fluorophores that absorb and reemit light (fluorescence effect). Light absorption depends on the chromophores’ content and their distribution within the organic matter.

During the last two decades, a great deal of attention has been focused on the optoelectronic properties of nanostructured semiconductors or Quantum Dots (QDs).

To access intrinsic amino acids, such as tryptophan, as probes, the UV excitation wavelengths for pulsed phosphorescence measurements have long been the preserve of low-repetition-rate gas-filled lamps or larger laser systems. Recent developments have enabled the use of interchangeable semiconductor diodes...

The fluorescence spectra of intrinsic protein fluorophores have been studied extensively and used in investigating biological events.

Quantum dots (QDs) are semiconducting spheres in the size typically in the range of 1 to 10nm. The size of these small spheres give quantum dots the semiconducting properties and resulting photoluminescence that would not necessarily occur for the same material on larger scales.

Samples can be valuable. Either you don’t want to waste them, or you may not have very much starting material. Biological proteins and enzymes, for example, are often obtained in small volumes and may be expensive.

Quantum dots (QDs) have potential applications in optoelectronics, biosensing, biolabeling, memory devices, and sources of laser light.

This technical note describes kinetic fluorescence as an analytical technique to quantify non-fluorescent species. The technique is applied to the determination of thiamine (vitamin B1) in solution.

HORIBA Jobin Yvon’s NanoLog® spectrofluorometer, specially optimized for recording near-IR fluorescence from nanoparticles, includes a double-grating excitation monochromator, imaging emission spectrograph with a selectable-grating turret, and a variety of detectors.

When a fluorophore absorbs a photon of light, an energetically excited state is formed. The fate of this species is varied, depending upon the exact nature of the fluorophore and its surroundings, but the end result is deactivation (loss of energy) and return to the ground state.

The choice of protecting group is of crucial importance in the success of many steps in organic synthesis and the manipulation of polyfunctional molecules, since they can prevent the formation of undesired side products and reactions.

The development and evaluation of UVA (320–400 nm) sunscreens is important because UVA sunlight can penetrate deep into human skin and cause severe internal damage, as well as erythema and photoaging.

Upconverting lanthanide-based nanomaterials exhibit a unique fluorescence anti-Stokes shift, which enables them to convert NIR wavelength excitation into visible shorter wavelength emissions (NIR to UV-Vis).

Tryptophan phosphorescence within protein molecules is gaining attention as a probe of protein dynamics and structure. The tryptophan phosphorescence lifetime, τ, varies with the protein molecule’s local environment and conformation.

Monitoring culture media conditions is highly important for industries in order to improve cell proliferation for applications such as regenerative medicines and protein synthesis.

Corrected emission spectra1 of carbon nanoparticles can provide excitation–emission matrices (EEMs) for a range of excitation wavelengths.

Improvements to the HORIBA Scientific NanoLog®, already the best spectrofluorometer for exploration of single-walled carbon nanotubes (SWCNTs), render it even more suitable for this application.

Single-wall carbon nanotubes (SWNTs), consisting of rolled-up single sheets of carbon atoms, have received much attention recently.

Fluorescence measurements with HORIBA Scientific spectrofluorometers are a sensitive tool for probing biochemical interactions such as molecular beacons and DNA.

Among the possible fluorescence biosensors for medical and biochemical monitoring and imaging are the flavonoids, compounds that occur in many plants and their products, such as tea, chocolate, and red wine.

Rapid mixing accessories to perform stopped flow measurements have found application in characterizing interactions and reactions occurring in solution. Reactants are expelled from syringes, mixed and injected into a flowcell.

The potential health benefits stemming from the antioxidant activity of curcumin, commonly found in turmeric (Curcuma longa L), has attracted the interest of several research groups.

Polarized light striking a fluorescent molecule results in polarized fluorescence. This polarized emission gradually returns to unpolarized fluorescence depending on rotational diffusion and other factors. Anisotropy is directly related to the polarization, and is the ratio of the polarized light component to the total light intensity.