Dual-Mode Sensor Based on a Single-Atom Cobalt Catalyst for Simultaneous Electrochemical and Colorimetric Detection...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Single-atom catalysts offer unique properties for sensing applications.
• Developing dual-functional catalysts enhances sensing platform performance.
• Zeolitic imidazolate framework-8 derived carbon matrices are effective supports.

Purpose of the Study:

• To synthesize and characterize a dual-functional single-atom catalyst (Co-N-C).
• To evaluate the electrochemical and colorimetric sensing performance of Co-N-C for bioactive small molecules.
• To investigate the mechanism behind the enhanced catalytic activity.

Main Methods:

• Facile host-guest synthesis strategy for Co-N-C.
• Electrochemical sensing using cyclic voltammetry and differential pulse voltammetry.
• Colorimetric assays utilizing peroxidase-like activity.
• Characterization of the catalyst structure and composition.

Main Results:

• Co-N-C demonstrated ultrahigh sensitivity for ascorbic acid (AA), dopamine (DA), and uric acid (UA) with low detection limits (electrochemical: 4.83 μM AA, 1.36 μM DA, 0.371 μM UA; colorimetric: 2.24 μM AA, 3.09 μM DA, 2.97 μM UA).
• The catalyst exhibited excellent selectivity and stability in electrochemical sensing.
• Nitrogen coordination precisely modulated cobalt's electronic structure, enhancing reactant affinity and electron transfer.

Conclusions:

• Co-N-C possesses dual catalytic functions for electrochemical and colorimetric sensing.
• The catalyst shows significant promise for high-performance biosensing applications.
• Precise control over single-atom catalyst design is crucial for optimizing catalytic efficiency and selectivity.