Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 2008-01-01

A novel and sensitive method for recognition and indirect determination of Al(III) in biological fluid based on the quenching of resonance Rayleigh scattering intensities of "Al(III)-EV-DNA" complexing system.

Xiufen Long, Desheng Li, Na Wang, Caihua Zhang, Qing Cao, Tao Xiancong, Shuping Bi

Index: Spectrochim. Acta. A. Mol. Biomol. Spectrosc. 69(1) , 142-7, (2008)

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Abstract

A novel method for recognition and indirect determination of Al(III) by using biological molecules has been established based on the quenching of RRS intensity. In the weak acidic medium, the reaction of ethyl violet (EV) and DNA would result in great enhancement of RRS intensity. However, the presence of Al(III) would lead to the decrease of the RRS intensity owing to the competition coordination of Al with DNA. The decreased intensity of RRS is directly proportional to the concentration of Al(III) in the range of (0.1-2.5)x10(-6) and (0.30-4.5)x10(-5)M, respectively. The method has high sensitivity and its detection limit (3sigma) is 3.6x10(-8)M. The characteristics of RRS spectra of the system, the optimum conditions of the reaction, and the reaction mechanism have been investigated. The method can recognize Al(III) selectively owing to its strong binding to the phosphate backbone of DNA, and has been applied to the determination of Al(III) concentration in synthetic biological samples with satisfactory results. Therefore, the proposed method is promising as an effective means for selective recognition and sensitive determination in situ of Al(III). Furthermore, this study would contribute to further understanding of the biological significance of Al neurotoxicity.