Determination of sildenafil in pharmaceutical formulations and synthetic urine using a composite electrode composed of acetylene black modified with silver nanoparticles and vegetable oil-derived polyurethane

Author(s)

da Silva, Rafael ; Alarcon, Rafael Turra ; Cavalheiro, Eder Tadeu Gomes

• Document type: Journal article
• Source: JOURNAL OF ELECTROANALYTICAL CHEMISTRY; v. 979, p. 12-pg., 2025-02-15.

Abstract

The development of electrode materials as alternatives to mercury and noble metals became an important branch of research in electroanalytical chemistry. Sildenafil is a widely marketed vasodilator drug used to treat erectile dysfunction. In this work, an acetylene black (AB)-based composite electrode with silver nanoparticles deposited on the surface and a vegetable oil polyurethane is proposed as a new voltammetric sensor. The deposition of silver on the AB surface was selected from different procedures. Thermal reduction in the presence of ethylene glycol resulted in higher yield, according to thermogravimetry and energy-dispersive X-ray spectroscopy. The modified AB particles were used as the conducting phase in composite electrodes agglutinated by polyurethane and the resulting devices after optimizing the experimental and instrumental conditions. The electrode was then used in the determination of sildenafil in pharmaceutical formulations and synthetic urine in 0.10 mol/L phosphate buffer, pH 3.0, resulting in a limit of detection of 0.89 mu mol/L. The results were in agreement with both the label values and the amount of drug spiked in the synthetic urine. The analyses of the pharmaceutical samples agreed within the 95 % confidence level, according to the Student's t-test, when compared to the chromatographic determination. (AU)

• FAPESP's process: 19/22217-8 - Thermoanalytical studies applied to antihepatitis and antiretroviral drugs of the protease inhibitor class: thermal behavior, decomposition intermediates, volatile characterization and polymorphism
• Grantee: Éder Tadeu Gomes Cavalheiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 22/15211-6 - Preparation and Application of Composite Electrodes Based on Graphite and Polymers: miniaturization, screen printed electrodes and flexible sensors
• Grantee: Éder Tadeu Gomes Cavalheiro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 21/14879-0 - New synthetic method of poly-hidroxyurethanes from triacylglycerol using catalysts or triacylmelamine to inhibition side reactions
• Grantee: Rafael Turra Alarcon
• Support Opportunities: Scholarships in Brazil - Post-Doctoral