Nano-arrayed Cu₂S@MoS₂ heterojunction SERS sensor for highly sensitive and visual detection of polystyrene in...

Area of Science:

• Environmental Science
• Materials Science
• Analytical Chemistry

Background:

• Microplastic and nanoplastic contamination poses a significant environmental and potential health risk.
• Existing detection methods often lack the sensitivity, stability, or cost-effectiveness required for widespread environmental monitoring.
• Novel sensor technologies are crucial for addressing the challenges in identifying and quantifying these pervasive pollutants.

Purpose of the Study:

• To develop and validate a novel, noble metal-free Surface-Enhanced Raman Spectroscopy (SERS) sensor for the sensitive detection of micro/nanoplastics.
• To engineer a Cu2S@MoS2 heterojunction with enhanced plasmonic and charge transfer properties for improved SERS performance.
• To assess the sensor's capability for both quantitative and visual identification of plastic contaminants in environmental samples.

Main Methods:

• Fabrication of a Cu2S@MoS2 heterojunction semiconductor sensor.
• Characterization of the sensor's Surface-Enhanced Raman Spectroscopy (SERS) properties, including sensitivity, enhancement factor (EF), and homogeneity.
• Application of the sensor for the detection of polystyrene (PS) micro/nanoparticles, evaluating limit of detection (LOD) and linear correlation (R2).

Main Results:

• The Cu2S@MoS2 sensor demonstrated high sensitivity with a methylene blue detection limit of 10^-8 M and an EF of 4.46 x 10^6.
• Excellent homogeneity was observed with a relative standard deviation (RSD) of 10.3%.
• The sensor successfully detected polystyrene particles down to 50 μg/mL with a strong linear correlation (R2 = 0.98), enabling both quantitative and visual identification.

Conclusions:

• The noble metal-free Cu2S@MoS2 heterojunction sensor provides a highly sensitive, stable, and cost-effective alternative for micro/nanoplastic detection.
• This technology significantly advances environmental monitoring capabilities for plastic contaminants.
• The sensor's dual quantitative and visual detection abilities offer a promising tool for environmental risk assessment and public health protection.