Novel Composite Electrode Based on Graphite and Polyurethane without Isocyanates for Electroanalysis with Modulated...

Area of Science:

• Materials Science
• Electrochemistry
• Green Chemistry

Background:

• Sustainable development and green chemistry principles are crucial for developing environmentally friendly materials.
• Renewable resources offer a sustainable alternative to petroleum-based feedstocks in material synthesis.

Purpose of the Study:

• To synthesize a novel composite material from renewable resources for electrochemical applications.
• To evaluate the composite's performance as a pH-sensitive electrode for detecting anionic and cationic species.
• To assess the analytical performance of the electrode for sildenafil citrate determination in various matrices.

Main Methods:

• Synthesis of a poly(hydroxyurethane) matrix from epoxidized macaw palm oil and CO2.
• Fabrication of a composite material by combining the polymer with graphite.
• Characterization of the composite's physical properties, including graphite dispersion and hydrophobicity.
• Electrochemical evaluation of the composite electrode's sensitivity to pH and its performance in detecting specific ionic species.
• Determination of sildenafil citrate in phosphate buffer solutions and synthetic urine using the developed electrode.

Main Results:

• A uniform graphite dispersion within the poly(hydroxyurethane) matrix was achieved, resulting in a moderately hydrophobic composite.
• The composite electrode exhibited sensitivity to pH variations and could detect both anionic (ferrocyanide) and cationic (hexammine ruthenium(III) chloride) species.
• The electrode demonstrated sensitive detection of sildenafil citrate with a low limit of detection (1.17 × 10⁻⁷ mol L⁻¹) and limit of quantification (3.90 × 10⁻⁷ mol L⁻¹).
• Accurate determination of sildenafil citrate in synthetic urine was achieved, with a recovery rate of 100 ± 1%.

Conclusions:

• The developed composite material, synthesized using green chemistry principles from renewable macaw palm oil, shows significant promise as a sustainable electrode material.
• The electrode's pH sensitivity and ability to detect various species, including sildenafil citrate, highlight its potential for analytical applications.
• This research contributes to the development of eco-friendly electrochemical sensors for pharmaceutical analysis and environmental monitoring.