Electrochemical sensing of sildenafil in pharmaceutical formulations using an (S,N)-doped reduced graphene oxide-modified electrode

• Nguyen Quang Man,
• Ngo Thi Thanh Xuan,
• Vo Thi Khanh Ly,
• Le Van Thanh Son,
• Le Duc Anh,
• Le Thi Hong Phong,
• Nguyen Hai Phong,
• Pham Khac Lieu,
• Le Lam Son and
• Dinh Quang Khieu

Beilstein J. Nanotechnol. 2026, 17, 1087–1102, doi:10.3762/bjnano.17.74

• , elemental mapping, photoluminescence, and Raman spectroscopy, confirming the successful incorporation of nitrogen and sulfur into the graphene framework. The obtained (S,N)-rGO was used to modify a glassy carbon electrode for the electrochemical determination of sildenafil (SDN). The modified electrode

• samples. The results were in good agreement with those from high-performance liquid chromatography, indicating that the proposed electrochemical method is reliable and suitable for practical analysis. Keywords: differential pulse voltammetry; electrode modifier; rGO; (S,N)-rGO; sildenafil; Introduction

• Sildenafil (SDN) is a widely prescribed phosphodiesterase type 5 (PDE-5) inhibitor used for the treatment of erectile dysfunction and pulmonary arterial hypertension. Its pharmacological activity is based on the selective inhibition of PDE-5, which increases the intracellular level of cyclic guanosine