Electrochemiluminescence of Tris(8-hydroxyquinoline-5-sulfonic acid)aluminum(III) in Aqueous Solution

Abstract

The electrochemiluminescence (ECL) of tris(8-hydroxyquinoline-5-sulfonic acid)aluminum(III) in aqueous solution is reported. ECL is generated by complexing aluminum ions with the chelating agent 8-hydroxyquinoline-5-sulfonic acid (HQS) to form Al(HQS)3, followed by oxidation in the presence of tri-n-propylamine (TPrA). The ECL intensity peaks a potential corresponding to oxidation of both TPrA and Al(HQS)3, and the ECL emission spectrum (λmax = 499 nm) matches the photoluminescence emission spectrum, indicating that the emission is from a Al(HQS)3* excited state. ECL efficiencies (φecl, photons generated per redox event) of 0.002 using Ru(bpy)32+ (φecl = 1) as relative standard. Conditions for ECL emission were optimized and used to generate a calibration curve that was linear over the 7 × 10-6−4 × 10-4 M (5−281 mg/L (ppm)) range with a theoretical limit of detection of 1 ppm. The ECL of several metal ions other than aluminum with HQS and effects on Al(HQS)3 ECL were also examined.

Department(s)

Chemistry and Biochemistry

Document Type

Article

DOI

https://doi.org/10.1021/ac026152p

Keywords

photoluminescence, solution chemistry, metals, aluminum, ions

Publication Date

2003

Journal Title

Analytical chemistry

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