A quinazoline derivative as quick-response red-shifted reporter for nanomolar Al3+ and applicable to living cell staining

Abstract

A newly synthesized and structurally characterized quinazoline derivative (L) has been shown to act as a quick-response chemosensor for Al³⁺ with a high selectivity over other metal ions in water–DMSO. In the presence of Al³⁺, L shows a red-shifted ratiometric enhancement in fluorescence as a result of internal charge transfer and chelation-enhanced fluorescence through the inhibition of a photo-induced electron transfer mechanism. This probe detects Al³⁺ at concentrations as low as 1.48 nM in 100 mM HEPES buffer (DMSO–water, 1 : 9 v/v) at biological pH with a very short response time (15–20 s). L was applied to biological imaging to validate its utility as a fluorescent probe for monitoring Al³⁺ ions in living cells, illustrating its value in practical environmental and biological systems.