Reusable, Ultrasensitive, Patterned Conjugated Polyelectrolyte-Surfactant Complex Film with a Wide Detection Range...

Area of Science:

• Materials Science
• Analytical Chemistry
• Sensor Technology

Background:

• Conjugated polyelectrolytes (CPEs) show promise for high-sensitivity detection in aqueous media.
• Current CPE sensors face real-world application challenges due to their reliance on solution-based operation.
• Solid-state operation is desirable for practical sensor applications.

Purpose of the Study:

• To develop and demonstrate a water-swellable (WS) CPE-based sensor operating in the solid state.
• To investigate the fabrication and performance of these novel WS CPE films for ion detection.
• To enable sensitive and selective detection of Cu2+ ions using a reusable solid-state sensor.

Main Methods:

• Fabrication of WS CPE films by immersing water-soluble CPE films in cationic surfactants.
• Characterization of film properties, including water swellability and fluorescence response.
• Testing sensor performance for Cu2+ detection, including sensitivity, selectivity, and reusability.
• Patterning of fluorescent films using a stamping method with different surfactants.

Main Results:

• WS CPE films exhibited rapid, limited water swellability without chemical crosslinking.
• The sensor demonstrated highly sensitive and selective detection of Cu2+ ions.
• Achieved a fluorescence quenching constant of 7.24 × 10^6 L mol^-1 and a detection limit of 4.38 nM (0.278 ppb) for Cu2+.
• The developed film was reusable and allowed for the fabrication of fluorescent patterns for wide-range Cu2+ detection (nM-mM).

Conclusions:

• Water-swellable CPE films offer a viable platform for solid-state sensors.
• The developed sensor provides a sensitive, selective, and reusable method for Cu2+ detection in aqueous environments.
• Patterning capabilities open avenues for integrated sensing systems with tunable detection ranges.