Simultaneous detection and removal of mercury ions in aqueous solution with fluorescent conjugated polymer-based sensor ensemble.

A water-soluble, sulfur-containing fluorescent conjugated polymer exhibits a visible fluorescence color change for detection of mercury in the presence of thymine. A new concept provides the design of a sensor ensemble using a simple combination method. This strategy avoids the need for complicated design and synthesis of a recognition group, eliminating the tedious synthetic efforts for the preparation of a sensor material.

Synthesis and electrostatic nano-assembly of water-soluble polybenzothiadiazole derivatives with long-wavelength emission in the solid states.

We have synthesized APBT and APTBT containing benzothiadiazole units by Suzuki cross-coupling reaction with good yield. The polymers showed blue emission colors in aqueous solutions, while long wavelength shift was observed in the solid state due to facilitated exciton migration. APBT and APTBT are water-soluble and highly-fluorescent conjugated polymers with negatively charged sulfonate side chains and thus they can be electrostatically assembled with oppositely charged polyelectrolyte such as cationic polymer, poly(dimethyldiallylammonium chloride) (PDAC) via layer-by-layer (LbL) deposition technique on a glass slide. According to the increased the number of bilayer, we found that the assembled film exhibited larger enhancement of the long wavelength emission relative to the blue emission, due to the increased excition migration.

Highly selective cysteine detection and bioimaging in zebrafish through emission color change of water-soluble conjugated polymer-based assay complex.

A new concept for rapid, label-free cysteine sensing method is proposed via possible naked eye-detection of red-to-blue emission color change. Intermolecular exciton migration in conjugated polyelectrolyte-based assay complex is adopted to enhance selectivity and sensitivity for cysteine sensing by formation and dissociation of polymer-Hg(2+)-thymine assay complex in the absence and presence of cysteine, respectively. The assay complex shows red emission due to cooperative aggregation of conjugated polyelectrolyte, thymine, and Hg(2+). Upon exposure to cysteine, the assay complex dissociates into individual molecules showing transparent, blue-emitting solution, because cysteine extracts Hg(2+) from the assay complex via more favorable binding between cysteine and Hg(2+).