Need for and Metrological Approaches Towards Standardization of Fluorescence Measurements from the View of National Metrology Institutes

Fluorescence standards: Classification, terminology, and recommendations on their selection, use, and production (IUPAC Technical Report)

“…Fluorescence standards can be divided into three general types or classes [49,50] depending on their scope and application: (i) instrument calibration standards, (ii) standards for the validation of the performance of fluorescence instruments, and (iii) application-specific standards.…”

“…The scope of these standards, which can be physical devices or reference materials, is to rule out instrumentation as a major source of variability and to yield instrument-independent, comparable fluorescence data. Typical applications are the determination of the wavelength accuracy of wavelengthselecting optical components using, e.g., atomic lamps or the spectral characteristics of fluorescence instruments [11,49,50] using, e.g., certified reference materials (CRMs) in the appropriate sample format at the sample position [67][68][69][70], see also Section 4.1.…”

“…These standards represent tools for the periodic verification of instrument performance [49,50]. Such standards can be either physical devices or reference materials and do not necessarily have to mimic the fluorescence properties of typically measured samples.…”

“…Examples include a sealed cuvette filled with deionized water in the case of the popular Raman test [71,72], or a fluorescent sample that is stable over time and after exposure to light, such as some solid, inorganic fluorophores. Examples of the latter are rare-earth-doped inorganic glasses, e.g., Standard Reference Materials (SRMs) 2940-2943 from the National Institute of Standards and Technology (NIST) [73,74] and the day-to-day intensity standards suggested by BAM [49], and rareearth-doped poly-tetrafluoroethylene, e.g., those sold by Avian Technologies and Labsphere.…”

“…Since the emission spectrum of a dye is comparatively narrow when compared to the emission spectrum of a calibrated lamp, see Fig. 2 (panels C and D), coverage of a broad spectral region requires the combination of different emission standards in a set [39,49,51,52,64,103]. The reliable determination of the overall spectral responsivity with such a set requires (1) the crossing of spectrally neighboring dye spectra at sufficient fluorescence intensities and (2) the statistically weighted combination of the wavelength-dependent quotients of the measured and the corrected (certified) emission spectra of the set components [64,103].…”