MCPA Optical Fiber Sensors via Molecularly Imprinted Polymers Combined with Intensity-Based and Plasmonic Platforms

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Environmental monitoring requires sensitive detection of herbicides like 4-chloro-2-methylphenoxyacetic acid (MCPA).
• Existing detection methods may lack cost-effectiveness or require complex fabrication.
• Plastic optical fibers (POFs) and molecularly imprinted polymers (MIPs) offer potential for low-cost sensor development.

Purpose of the Study:

• To develop and evaluate two distinct low-cost optical-chemical sensors for MCPA detection.
• To compare the performance of POF-MIP based sensors with existing electrochemical techniques.
• To assess the practical applicability of the developed sensors in real environmental samples.

Main Methods:

• Fabrication of two sensor types: an optical splitter using modified POFs and MIPs, and a surface plasmon resonance (SPR) D-shaped POF platform with MIPs.
• Utilized white light sources and spectrometers for sensor testing.
• Analyzed MCPA detection limits, ranges, and selectivity using MIP binding sites.
• Performed recovery tests on real environmental samples.

Main Results:

• Both POF-MIP sensors demonstrated high selectivity for MCPA.
• Achieved similar low detection limits (LODs) of 3 nM and detection ranges (3 nM–500 nM).
• Exhibited superior performance compared to previously reported electrochemical methods with the same MIP.
• Real sample tests showed good recovery rates (82%–116%), indicating practical applicability.
• The POF-MIP splitter sensor offers a fabrication route avoiding expensive processes.

Conclusions:

• Developed cost-effective POF-MIP optical sensors for MCPA detection with excellent performance.
• The sensors are suitable for environmental monitoring due to their sensitivity, selectivity, and applicability in real samples.
• The POF-MIP splitter sensor presents an advantageous, low-cost fabrication alternative.