A fluorescent probe for detection of histidine in cellular homogenate and ovalbumin based on the strategy of click chemistry.

A sensitive and selective fluorescent probe for histidine has been designed by taking the advantages of the click chemistry reaction (copper(I)-catalyzed azides and alkynes cycloaddition) and the inhibition of copper(II)-induced ascorbate oxidation by histidine. The fluorescence intensity decreases with the increasing of histidine concentration, and the value of F₀/F shows a good linear relationship with the concentration of histidine over the range of 0.5-100 μM with a detection limit of 76 nM, which is lower than those of many other fluorescent sensors. Moreover, the sensor has high specificity for histidine compared to some potential interferents, such as other amino acids and metal ions. In addition, the proposed sensor has been applied to determine histidine in cellular homogenate and ovalbumin samples with satisfactory results. The preferable simplicity, sensitivity and specificity for the detection of histidine indicate that the proposed sensor have potential prospect in environmental and biomedical analysis.