Development of a surface-modified paper-based colorimetric sensor using synthesized Ag NPs-alginate composite

Area of Science:

• Analytical Chemistry
• Nanotechnology
• Materials Science

Background:

• Increasing demand for chemical compound detection sensors in analytical chemistry.
• Advancements in nanotechnology driving the development of efficient nanomaterials for biosensing.
• Need for cost-effective and rapid synthesis methods for nanomaterials.

Purpose of the Study:

• To synthesize silver nanoparticles (Ag NPs) using a fast and cost-effective microwave-assisted method with sodium alginate.
• To develop a paper-based sensor utilizing Ag NPs-alginate composite for hydrogen peroxide (H₂O₂) detection.
• To evaluate the sensing characteristics, sensitivity, and selectivity of the developed paper sensor.

Main Methods:

• Synthesis of Ag NPs via microwave irradiation using sodium alginate as a reducing and capping agent.
• Characterization of Ag NPs using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).
• Fabrication of a paper-based sensor by modifying paper with Ag NPs-alginate composite and detecting H₂O₂ via colorimetric changes analyzed by smartphone camera and RGB app.

Main Results:

• Successfully synthesized Ag NPs with an average particle size of 10 nm, confirmed by XRD and XPS.
• Developed a paper sensor capable of detecting H₂O₂ in the concentration range of 0.1–10 mM.
• Demonstrated a piecewise linear relationship between RGB intensity and H₂O₂ concentration (R² values of 0.97 and 0.9778).

Conclusions:

• The synthesized Ag NPs-alginate composite is effective for developing a sensitive and selective paper-based sensor.
• The developed sensor offers a cost-effective and rapid method for real-time H₂O₂ analysis.
• This nanotechnology-based approach holds potential for practical applications in chemical sensing.