Rare Earth as Fluorescence Probe to Determine 3,4-Dihydroxydroxyphenylalanine

Abstract

3,4-Dihydroxyphenylalanine can complex with Tb (III) at pH 8.0–8.5, with emission of the characteristic fluorescence of Tb(III). This method can be used for selectively determinating 3,4-dihydroxyphenylalanine in the presence of most amino acids. The experiment showed that the fluorescence intensity is a linear function of 3,4-dihydroxyphenylalanine concentration in the range of 1.1×10⁻⁸mol/1 to 1.0×10⁻⁵mol/1. The detection limit is 5×10⁻⁹mol/1. The composition ratio of Tb to 3,4-dihydroxyphenylalanine in the complex is 1:1.

Key Words:

• 3,4-Dihydroxyphenylalanine
• Tb (III)
• Fluorimetry