Ionic strength-responsive microcapsules with auto-fluorescence were fabricated by incubation of poly (allylamine hydrochloride) (PAH)-doped CaCO3 particles in triethylamine (Et3N), followed by core removal using HCl. Based on the combination of hydrophobic interaction and hydrogen bonding, PAH and Et3N formed a complex with a molar ratio of 3:1 (repeating unit of PAH: Et3N). The as-prepared capsules showed extraordinary stability against 1 M HCl, 1 M NaOH and 6 M urea solutions, and could swell or shrink reversibly in response to the ionic strength. Furthermore, the capsules possessed auto fluorescence, allowing easily tracking of capsules during applications. Such interaction may be expanded to formation of stimuli-responsive multilayer films and other colloidal particles. (C) 2017 Elsevier Inc. All rights reserved.