PAS1-modified optical SIS sensor for highly sensitive and specific detection of toluene

Area of Science:

• Biosensing
• Chemical Sensing
• Surface Science

Background:

• Accurate detection of toluene is crucial for environmental and industrial monitoring.
• Existing methods for toluene detection may lack sensitivity or specificity.
• Development of novel biosensors offers potential for improved toluene detection.

Purpose of the Study:

• To develop and evaluate a novel solution immersed silicon (SIS) sensor modified with a bio-receptor for selective toluene detection.
• To investigate the specificity and sensitivity of the PAS1 bio-receptor for toluene capture.
• To establish a high-fidelity system for accurate toluene quantification.

Main Methods:

• Immobilization of PAS1 bio-receptor, including wild-type and toluene-binding defective mutants (F46A, F79Y), onto SiO2 surfaces using silica binding peptide (SBP) for SIS ellipsometric sensing.
• Evaluation of the PAS1-modified SIS sensor's response to toluene exposure.
• Assessment of sensor specificity using negative controls such as benzene, phenol, xylene, and 4-nitrophenol.

Main Results:

• The PAS1-modified SIS sensor exhibited a significant up-shift in Psi (Ψ) upon exposure to toluene, indicating successful detection.
• A low limit of detection (LOD) of 0.1 μM was achieved for toluene detection with the wild-type PAS1 sensor.
• No significant changes in Psi (Ψ) were observed when the sensor was exposed to benzene, phenol, xylene, or 4-nitrophenol, demonstrating high specificity.

Conclusions:

• The PAS1-modified SIS sensor provides a highly selective and accurate method for toluene detection.
• The use of SBP facilitated efficient immobilization of the bio-receptor for sensor construction.
• This novel biosensor system holds promise for reliable toluene monitoring applications.