A new fluorescent multi-functional monomer (E)-3′,6′-bis (allyloxy)-2-((thiazol-2-ylmethylene)amino)-4a′,9a′-dihydrospiro[isoindoline-1,9′-xanthen]-3-one (ATMIX) was successfully synthesized for the first time. The obtained ATMIX not only exhibited fluorescence on–off characteristics toward Ag(I), but also could produce radical polymerization with cross-linkers. Based on ATMIX, a novel ion-imprinted fluorescent on–off sensor (IIFOS) was fabricated successfully for selective recognition of Ag(I). The morphology, structure and fluorescent property of IIFOS was characterized by infrared spectroscopy, scanning electron microscopy (SEM) and fluorescent spectrometry. The results indicated that the obtained IIFOS exhibited high selective fluorescence on–off characteristics toward Ag(I) based on the mechanism of photoinduced electron transfer. What is more, the IIFOS is reusable and has been applied to detect Ag(I) in water sample with satisfactory recoveries.

Based on the fluorescence quenching mechanism of Fe3+ to moxifloxacin (MOX), a fluorescence probe has been found and exhibits high sensitivity, unique selectivity and good stability toward Fe3+. Moreover, the MOX probe can rapidly response to the change of Fe3+ concentration in pure aqueous solution. The MOX probe was utilized for quantitative determination of Fe3+ in real water sample, showing a good linear relationship (R = 0.9980) between (F0–F) and [Fe3+]1/2 at the Fe3+ concentration from 0.05–15 μM. The detection limit was found to be 0.032 μM, which is much lower than that of most literature reported. Furthermore, by merging the MOX probe and a Y-tape fiber-optic spectrometer, a fluorescent fiber-optic chemosensor has been developed to quantitatively monitor Fe3+ in HepG2 living cells in vivo. The monitoring results are consistence with that obtained from the confocal imaging technique. The established method possesses the advantages of fast responsive, high sensitivity, unique selectivity, very stability and good repeatability for quantitative monitoring Fe3+ in real water and HepG2 living cells. In addition, the complex mechanism of MOX toward Fe3+ has also been explored by Fourier transform infrared spectroscopy (FT-IR) and mass spectra (MS) in the present work.

•Hourly detection method was developed for ambient carbonyls by coupling MEKC and MISPE.•The unreacted DNPH was removed by MISPE cartridge with DNAN as dummy template.•A high enrichment factor has been achieved owing to the sample clean-up.•Fixed the problems that the commercial C18-SPE cannot clean-up DNPH from carbonyl-DNPH derivatives.A novel method coupling molecular imprinting solid-phase extraction (MISPE) and micellar electrokinetic capillary chromatography (MEKC) was developed to enable the hourly determination of low level of ambient carbonyls, and study their partition between gaseous phase and particulate phase. With 2,4-dinitroaniline (DNAN) as dummy imprinting template, the unreacted 2,4-Dinitrophenylhydrazine (DNPH) in sampling solution could be removed effectively using MISPE, and an average recovery of 97 ± 5.3% (n = 5) for the carbonyl-DNPH derivatives was achieved. Owing to the high enrichment due to sample clean-up, and the improvement of MEKC separation efficiency, many low abundant carbonyls could be detected by hourly in the field study.

In this paper, a fluorescein spirolactam derivative, ((E)-3′,6′-dihydroxy-2-((thiazol-2-ylmethylene)aminospiro[isoindoline-1,9′-xanthen]-3-one) (HTMIX), was synthesized and used as a turn-on fluorescence probe for the detection of silver ion in aqueous solution. The binding mechanism of HTMIX to Ag+ was evaluated using the Hildebrand–Benesi equation based on a 1:1 binding model with R = 0.9993. And the influence of sixteen common metal ions on the fluorescence intensities of HTMIX–Ag+ solution was investigated in detail. The results show that HTMIX exhibited high selectivity towards Ag+ in a 20% ethanol solution. The obtained fluorescence probe was used for the quantitative determination of Ag+ with a good linear range from 0.1 μM to 10 μM (R = 0.9969) and a satisfactory detection limit of 0.08 μM. In addition, the present probe has been further used for the detection of Ag+ in tap water, river water and lake water. And the accuracy of the results obtained by the proposed method was in good agreement with that obtained by flame atomic absorption spectrometry.

In this paper, a fluorescein spirolactam derivative, ((E)-3′,6′-dihydroxy-2-((thiazol-2-ylmethylene)aminospiro[isoindoline-1,9′-xanthen]-3-one) (HTMIX), was synthesized and used as a turn-on fluorescence probe for the detection of silver ion in aqueous solution. The binding mechanism of HTMIX to Ag+ was evaluated using the Hildebrand–Benesi equation based on a 1:1 binding model with R = 0.9993. And the influence of sixteen common metal ions on the fluorescence intensities of HTMIX–Ag+ solution was investigated in detail. The results show that HTMIX exhibited high selectivity towards Ag+ in a 20% ethanol solution. The obtained fluorescence probe was used for the quantitative determination of Ag+ with a good linear range from 0.1 μM to 10 μM (R = 0.9969) and a satisfactory detection limit of 0.08 μM. In addition, the present probe has been further used for the detection of Ag+ in tap water, river water and lake water. And the accuracy of the results obtained by the proposed method was in good agreement with that obtained by flame atomic absorption spectrometry.