A Novel Impedimetric Sensor Based on Cyanobacterial Extracellular Polymeric Substances for Microplastics Detection

Area of Science:

• Environmental Science
• Materials Science
• Analytical Chemistry

Background:

• Cyanobacterial extracellular polymeric substances (EPS) are increasingly recognized for biomedical and food applications.
• The potential of EPS as a sensor coating for microplastic detection remains largely unexplored.
• Microplastic pollution is a growing environmental concern requiring sensitive detection methods.

Purpose of the Study:

• To investigate the application of cyanobacterial EPS as a sensitive membrane for microplastic detection.
• To develop and characterize an impedimetric sensor based on EPS for microplastic quantification.
• To evaluate the sensor's performance in detecting various microplastic types and concentrations.

Main Methods:

• EPS was extracted from cyanobacteria and deposited as a membrane on a gold electrode.
• Electrochemical impedance spectroscopy (EIS) was employed to detect microplastics.
• Surface characterization was performed using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), and X-ray Spectroscopy.

Main Results:

• The EPS membrane exhibited a homogenous structure with abundant functional groups, confirmed by SEM, FTIR, and X-ray spectroscopy.
• The EPS-based impedimetric sensor successfully detected four types of microplastics ranging from 0.1 µm to 1 mm.
• A low limit of detection (LOD) of 10⁻¹¹ M was achieved for microplastic detection.

Conclusions:

• Cyanobacterial EPS is a viable and novel material for developing sensitive impedimetric sensors.
• This EPS-based sensor represents a new approach for the quantification of low microplastic concentrations.
• The study highlights a promising application of EPS in environmental monitoring and microplastic analysis.