Sensitive and Specific Detection of l‑Lactate Using an AIE-Active Fluorophore

l-Lactate is a vital biomarker for many diseases and physiological fatigue. An AIE-active fluorophore (TPE-HPro) is combined with l-lactate oxidase (LOx) to determine l-lactate in aqueous fluid. The assay shows excellent sensitivity and anti-interference performance with a limit of detection (LOD) of 5.5 μM. In addition, sensitive detection of l-lactate is achieved even in a protein-rich environment. It is proposed that quantification of l-lactate be performed at 20 or 60 min in the current method. These characteristics endow the fluorometric assay with great potential for biomedical diagnostics

Thiol-Reactive Molecule with Dual-Emission-Enhancement Property for Specific Prestaining of Cysteine Containing Proteins in SDS-PAGE

1-[4-(Bromomethyl)­phenyl]-1,2,2-triphenylethene (<b>2</b>) was synthesized and evaluated for specific fluorescent prestaining of proteins containing cysteine (Cys) in SDS-PAGE. The molecule showed classic aggregation-induced emission (AIE) property in protein labeling and its quantum efficiency was further enhanced upon reacting with Cys. The parameters of reaction such as labeling time and concentration of dye and reducing reagent-tris­(2-carboxyethyl)­phosphine (TCEP) were examined to obtain the optimal labeling condition. In addition to its specific labeling effect, molecule <b>2</b> also showed its advantage over traditional self-quenching dyes through labeling Cys containing BSA with different dye/Cys ratios

High Thermoelectric Performance in Crystallographically Textured n‑Type Bi₂Te_3–<i>x</i>Se_<i>x</i> Produced from Asymmetric Colloidal Nanocrystals

In the present work, we demonstrate crystallographically textured n-type Bi₂Te_3–<i>x</i>Se_<i>x</i> nanomaterials with exceptional thermoelectric figures of merit produced by consolidating disk-shaped Bi₂Te_3–<i>x</i>Se_<i>x</i> colloidal nanocrystals (NCs). Crystallographic texture was achieved by hot pressing the asymmetric NCs in the presence of an excess of tellurium. During the hot press, tellurium acted both as lubricant to facilitate the rotation of NCs lying close to normal to the pressure axis and as solvent to dissolve the NCs approximately aligned with the pressing direction, which afterward recrystallize with a preferential orientation. NC-based Bi₂Te_3–<i>x</i>Se_<i>x</i> nanomaterials showed very high electrical conductivities associated with large charge carrier concentrations, <i>n</i>. We hypothesize that such large <i>n</i> resulted from the presence of an excess of tellurium during processing, which introduced a high density of donor Te_Bi antisites. Additionally, the presence in between grains of traces of elemental Te, a narrow band gap semiconductor with a work function well below Bi₂Te_3–<i>x</i>Se_<i>x</i>, might further contribute to increase <i>n</i> through spillover of electrons, while at the same time blocking phonon propagation and hole transport through the nanomaterial. NC-based Bi₂Te_3–<i>x</i>Se_<i>x</i> nanomaterials were characterized by very low thermal conductivities in the pressing direction, which resulted in <i>ZT</i> values up to 1.31 at 438 K in this direction. This corresponds to a <i>ca</i>. 40% <i>ZT</i> enhancement from commercial ingots. Additionally, high <i>ZT</i> values were extended over wider temperature ranges due to reduced bipolar contribution to the Seebeck coefficient and the thermal conductivity. Average <i>ZT</i> values up to 1.15 over a wide temperature range, 320 to 500 K, were measured, which corresponds to a <i>ca</i>. 50% increase over commercial materials in the same temperature range. Contrary to most previous works, highest <i>ZT</i> values were obtained in the pressing direction, corresponding to the <i>c</i> crystallographic axis, due to the predominance of the thermal conductivity reduction over the electrical conductivity difference when comparing the two crystal directions