A biphasic mercury-ion sensor: exploiting microfluidics to make simple anilines competitive ligands.

Combining the molecular wire effect with a biphasic sensing approach (analyte in water, sensor-dye in 2-methyltetrahydrofuran) and a microfluidic flow setup leads to the construction of a mercury-sensitive module. We so instantaneously detect Hg(2+) ions in water at a 500 µM concentration. The sensor, conjugated non-water soluble polymer 1 (XFPF), merely supports dibutylaniline substituents as binding units. Yet, selective and sensitive detection of Hg(2+) -ions is achieved in water. The enhancement in sensory response, when comparing the reference compound 2 to that of 1 in a biphasic system in a microfluidic chip is >10(3) . By manipulation of the structure of 1, further powerful sensor systems should be easily achieved.

Development of Thermally Activated Delayed Fluorescence Materials with Shortened Emissive Lifetimes.

We have prepared a thermally activated delayed fluorescence (TADF) capable molecular system carrying halogen substituents at the carbazole units. The attachment of the halogen atoms considerably decreases the half-life of the delayed fluorescence. The effect is significant. The heavier the halogen, the greater the effect. Our materials have the shortest reported emissive lifetimes for TADF achieved to date. Intersystem crossing (ISC) is improved through the heavy atom effect, yet high quantum yields are achieved both in solution as well as in thin doped films. The simple and efficient synthesis of our targets uses inexpensive and easily obtained starting materials.

Amine detection with distyrylbenzenedialdehyde-based Knoevenagel adducts.

Eight acceptor-substituted distyrylbenzene (DSB) derivatives were obtained by postfunctionalization of dialdehyde precursor 1 using Knoevenagel condensation. Solubility in a water/THF 9:1 mixture was achieved through the addition of branched oligoethylene glycol side chains. The acceptor compounds discriminate primary and secondary amines in aqueous solution. The fluorescence responses were analyzed by the multivariate analysis of variance (MANOVA) protocol, a statistical tool. In contrast to 1, the adducts show reactivity toward secondary and aromatic amines. Nitroolefin 2f is the most active dosimeter molecule. Reaction with amines is completed after less than 3 min, and the limit of detection (LOD) is improved by a factor of 10. Propylenediamine can be detected at 75 µM. This is a 10-fold improvement for the detection limit when compared to the detection limit of the starting dialdehyde.