Fluorescence ‘turn-on’ detection of Cu ions with aggregation-induced emission-active tetraphenylethene based on click chemistry

A fluorometric sensor for detection of Cu²⁺ ions in aqueous solution with aggregation-induced emission-active tetraphenylethene based on click chemistry is reported. Upon addition of Cu²⁺, a reaction of azide-modified tetraphenylethene and diethylene glycol dipropiolate in the presence of sodium ascorbate proceeded to yield covalently cross-linked networks, resulting in a dramatic enhancement of fluorescence. This assay showed high selectivity for Cu²⁺ ions even in the presence of other metal ions in a mixture.