Catalytic Signal Amplification Using a Heck Reaction. An Example in the Fluorescence Sensing of Cu(II)

• Published in: Journal of the American Chemical Society Vol. 126; no. 45; pp. 14682 - 14683
• Main Authors: Wu, Qiaoyin, Anslyn, Eric V
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 17.11.2004
• Subjects: Analytical chemistry; Chemistry; Exact sciences and technology; General, instrumentation; Intramolecular reaction; Fluorescence detector; Catalytic reaction; Nitrogen heterocycle; Organic ligand; Transition metal Complexes; Chemical sensor; Copper Complexes
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja0401038

Catalytic signal enhancement using an organometallic reaction is demonstrated. The reactivity of a Heck cross-coupling reaction that creates a fluorophore is modulated by the addition of a polyazacyclam inhibitor. The inhibitor will complex with Cu(II), which restores the activity of the Pd(II). The addition of Cu(II) therefore leads to the generation of fluorescence, thereby creating a very sensitive assay for Cu(II). The rate of the Heck reaction is followed by monitoring emission as a function of time. The rate is proportional to the Cu(II) concentration and correlates to the affinity of the inhibitor to various metals. This strategy represents a general technique that can be exploited with other catalytic organometallic reactions.