A nanozyme-based colorimetric sensor array as electronic tongue for thiols discrimination and disease identification

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Biomedical Sensing

Background:

• Thiol analysis is critical for disease diagnosis, but differentiating similar thiol structures poses a significant challenge.
• Existing methods struggle with the sensitive and accurate determination of various thiols due to structural similarities.

Purpose of the Study:

• To develop a nanozyme-based colorimetric sensor array as an electronic tongue for discriminating and quantifying thiols.
• To create a system capable of identifying thiol-associated diseases through advanced data analysis.

Main Methods:

• Fabrication of sensing units by coordinating terephthalic acid modified graphene quantum dots (TPA@GQDs) with Fe²⁺, Cu²⁺, and Zn²⁺.
• Utilizing the peroxidase-like catalytic activity of metal ion-TPA@GQD ensembles and its inhibition by thiols.
• Employing 3,3',5,5'-tetramethylbenzidine (TMB) and hydrogen peroxide (H₂O₂) for colorimetric signal generation.

Main Results:

• Achieved differential colorimetric signals (fingerprints) for six thiol analytes based on varying inhibition of catalytic activity.
• Successfully discriminated thiols using linear discriminant analysis (LDA) with a detection limit of 50 nM.
• Demonstrated discrimination of varying thiol concentrations and thiol mixtures.

Conclusions:

• The proposed nanozyme sensor array functions as an effective electronic tongue for sensitive and selective thiol detection.
• The system's ability to generate unique fingerprints enables accurate discrimination of complex thiol samples.
• Integration with machine learning allows for the identification of thiol-associated diseases, offering a promising tool for medical diagnosis.