Visualized concentration sensors based on fluorescence indication in a dye-doped polymer microwire

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Accurate detection of aqueous solution concentrations is crucial in various scientific and industrial applications.
• Existing micro/nanofiber sensors often face challenges with stability and weak signal detection.

Purpose of the Study:

• To develop a visualized microwire sensor for direct and stable detection of aqueous solution concentrations.
• To utilize fluorescence indication and image analysis for quantitative sensing.

Main Methods:

• Polymer microwires (PMWs) doped with Rhodamine (RhB) were fabricated and used as the sensory element.
• Waveguiding excitation method was employed to excite the fluorescence of the RhB-doped PMWs.
• Image processing and information extraction algorithms were used to analyze fluorescent microimages and extract the period length of oscillations.

Main Results:

• Stable, periodic fluorescence oscillations were observed in RhB-doped PMWs.
• The period length of these oscillations was found to be dependent on the concentration of aqueous solutions (NaCl, KCl, sucrose).
• Detection limits for the solutions were estimated to be around 1.5 × 10⁻⁴%, with significant period length changes observed for a 1.0% concentration change.

Conclusions:

• The proposed dye-doped PMW sensors enable direct visualized detection of concentrations.
• This approach overcomes challenges related to sensor stability and weak signal detection.
• The method offers a potentially stable and cost-effective strategy for micro/nanofiber sensor applications.