Acetaldehyde, acrolein, and formaldehyde are the principal toxic aldehydes present in cigarette smoke and contribute to the risk of cardiovascular disease and noncancerous pulmonary disease. The rapid growth of the use of electronic cigarettes (e-cigarettes) has raised concerns over emissions of these harmful aldehydes. This work determines emissions of these aldehydes in both free and bound (aldehyde–hemiacetal) forms and other carbonyls from the use of e-cigarettes. A novel silicon microreactor with a coating phase of 4-(2-aminooxyethyl)-morpholin-4-ium chloride (AMAH) was used to trap carbonyl compounds in the aerosols of e-cigarettes via oximation reactions. AMAH–aldehyde adducts were measured using gas chromatography–mass spectrometry. 1H nuclear magnetic resonance spectroscopy was used to analyze hemiacetals in the aerosols. These aldehydes were detected in the aerosols of all e-cigarettes. Newer-generation e-cigarette devices generated more aldehydes than the first-generation e-cigarettes because of higher battery power output. Formaldehyde–hemiacetal was detected in the aerosols generated from some e-liquids using the newer e-cigarette devices at a battery power output of 11.7 W and above. The emission of these aldehydes from all e-cigarettes, especially higher levels of aldehydes from the newer-generation e-cigarette devices, indicates the risk of using e-cigarettes.

Novel pyrene-and anthracene-based Schiff base derivatives P1 and A1 were synthesized via a one-pot reaction and utilized as fluorescence turn-on sensors towards Cu 2+ and Fe 3+ ions, respectively, and for aggregation induced emissions (AIEs). P1 in CH 3 CN and A1 in THF illustrated the fluorescence turn-on sensing towards Cu 2+ and Fe 3+ ions, respectively, via chelation enhanced fluorescence (CHEF) through excimer (P1-P1* and A1-A1*) formation. The 2 : 1 stoichiometry of the sensor complexes (P1 + Cu 2+ and A1 + Fe 3+ ) were calculated from Job plots based on UV-Vis absorption titrations. In addition, the binding sites of sensor complexes (P1 + Cu 2+ and A1 + Fe 3+ ) were well established from the 1 H NMR titrations and supported by the fluorescence reversibility by adding metal ions and PMDTA sequentially.The detection limits (LODs) and the association constant (K a ) values of P1 + Cu 2+ and A1 + Fe 3+ sensor responses were calculated by standard deviations, linear fittings and from their fluorescence binding isotherms. More importantly, P1 + Cu 2+ and A1 + Fe 3+ sensors were found to be active in wide ranges of pHs (1-14 and 2-14, respectively). Moreover, the time effect along with the enhancements of quantum yield (F) and time resolved photoluminescence (TRPL) decay constant (s) towards sensor responses were investigated. Similarly, P1 in CH 3 CN and A1 in THF showed AIEs by increasing the aqueous media concentration from 0% to 90%, with altered fluorescence peak shifts (red and blue shifts, respectively). As well as s value enhancements, the F values of 0.506 and 0.567 (with 630-and 101-fold enhancements) were acquired for P1 in CH 3 CN : H 2 O (20 : 80) and A1 in THF : H 2 O (40 : 60), respectively.

We discuss and review the strategies of metal-based receptors targeting phosphate.