Dual Z-scheme In₂S₃/Bi₂S₃/ZnS heterojunction with broad-spectrum response as a photoactive material for ultrasensitive detection of environmental Pollutant tetracycline

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Environmental pollution by antibiotics like tetracycline (TC) poses a significant threat.
• Existing photoelectrochemical (PEC) biosensors often suffer from low sensitivity and background noise.
• Developing highly sensitive and reliable methods for TC detection is crucial for environmental monitoring and food safety.

Purpose of the Study:

• To develop a novel dual Z-scheme heterojunction In2S3/Bi2S3/ZnS (IBZS) with a core-shell structure for enhanced PEC performance.
• To establish a highly sensitive PEC biosensor for the ultrasensitive detection of tetracycline (TC).
• To mitigate the DNA duplex breathing effect and suppress background noise for improved detection accuracy.

Main Methods:

• Fabrication of a dual Z-scheme heterojunction IBZS material with a core-shell structure.
• Construction of a PEC biosensor utilizing the IBZS material.
• Implementation of a target-triggered entropy-driven DNA reaction (TEDR) strategy to enhance signal-to-noise ratio.
• Optimization of the PEC detection parameters for TC analysis.

Main Results:

• The dual Z-scheme heterojunction IBZS exhibited a strong PEC response due to broad-spectrum absorption and efficient carrier migration.
• The redesigned TEDR effectively suppressed nonspecific background noise, significantly enhancing detection sensitivity.
• The developed PEC biosensor achieved ultrasensitive detection of TC in the range of 1.0 fM to 10 nM.
• An exceptionally low detection limit of 0.54 fM for TC was achieved, surpassing current methods.

Conclusions:

• The novel dual Z-scheme heterojunction IBZS material and TEDR strategy provide a high-performance PEC biosensor for ultrasensitive TC detection.
• This approach offers a promising new avenue for designing advanced PEC photoactive materials for environmental pollution monitoring.
• The developed biosensor is expected to be valuable for analyzing antibiotics in environmental samples and ensuring food quality control.