CdSe/ZnS quantum dots-doped polymer optical fiber microprobe for pH sensing

Area of Science:

• Biomedical Engineering
• Materials Science
• Optical Sensing

Background:

• Accurate pH monitoring is vital for physiological processes and cellular functions.
• Optical fiber pH sensors offer advantages but face challenges like poor biocompatibility and surface instability.
• Existing silica optical fiber sensors require complex modifications and lack safety for biological use.

Purpose of the Study:

• To develop a novel, biocompatible, and stable optical fiber pH sensor for biological applications.
• To overcome the limitations of current silica-based optical fiber pH sensors.
• To create a compact and flexible pH sensing probe with enhanced safety and functionality.

Main Methods:

• Fabrication of a polymer optical fiber microprobe (POF MP) doped with Cadmium Selenide/Zinc Sulfide (CdSe/ZnS) quantum dots.
• Utilizing free radical photopolymerization to grow the POF MP at the tip of a silica optical fiber.
• Characterization of the sensor's sensitivity, linearity, reversibility, and reusability across a wide pH range.

Main Results:

• The developed sensor exhibits high compactness, flexibility, biocompatibility, and structural stability.
• The sensor demonstrates a sensitivity of 0.18097/pH within the pH range of 4.5 to 9.0.
• A highly linear correlation (R² = 0.99448) between fluorescence intensity and pH was observed, along with good reversibility and reusability.

Conclusions:

• The novel quantum dot-doped polymer optical fiber microprobe sensor provides a promising solution for real-time pH monitoring in biological environments.
• This sensor technology offers advantages in biosensing, microenvironment monitoring, and potential therapeutic applications due to its enhanced properties.
• The controllable size and improved characteristics of the POF MP sensor pave the way for advanced biomedical sensing technologies.