What are the advantages of fluorescence measurement?
Sensitivity: Limits of detection depend to a large extent on the properties of the sample being measured, but, on the whole, fluorescence achieves a high level of sensitivity. Detectability to parts per billion or even parts per trillion is common for most analytes. Fluorometers achieve 1,000 to 500,000 times better limits of detection as compared to spectrophotometers.
Specificity: Spectrophotometers merely absorb light. Spectrophotometric techniques are prone to interference problems because many materials absorb light, making it difficult to isolate the targeted analyte in a complex matrix. Fluorometers are highly specific and less susceptible to interferences because fewer materials absorb and also emit light (fluoresce). And, if non-target compounds do absorb and emit light, it is rare that they will emit the same wavelength of light as target compounds.
Simplicity and Speed: Fluorometry is a relatively simple analytical technique. Fluorometry’s sensitivity and specificity reduce or eliminate the sample preparation procedures often required to concentrate analytes or remove interferences from samples prior to analysis. This reduction in or elimination of sample preparation time not only simplifies, but also expedites the analysis.