Electrochemical detection of sulfanilamide using tannic acid exfoliated MoS2 nanosheets combined with reduced graphene oxide/graphite

• Published in: Environmental research 2024-05, Vol.248, p.118391-118391, Article 118391
• Main Authors: Luo, Yiran, Barwa, Tara N., Dempsey, Eithne, Karthik, Raj, Shim, J.J., Sukanya, Ramaraj, Breslin, Carmel B.
• Format: Article
• Language: English
• Subjects: Electrochemical sensor; Graphite flakes; MoS2; Reduced graphene oxide; Sulfanilamide; Sulfonamide; Tannic acid exfoliation
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2024.118391

Sulfonamides are a family of synthetic drugs with a broad-spectrum of antimicrobial activity. Like other antimicrobials, they have been found in aquatic environments, making their detection important. Herein, an electrochemical sensor was designed using tannic acid exfoliated few-layered MoS2 sheets, which were combined with a mixture of reduced graphene oxide (rGO) and graphite flakes (G). The rGO/G was formed using electrodeposition, by cycling from −0.5 to −1.5 V in an acidified sulfate solution with well dispersed GO and G. The exfoliated MoS2 sheets were drop cast over the wrinkled rGO/G surface to form the final sensor, GCE/rGO/G/ta-MoS2. The mixture of rGO/G was superior to pure rGO in formulating the sensor. The fabricated sensor exhibited an extended linear range from 0.1 to 566 μM, with a LOD of 86 nM, with good selectivity in the presence of various salts found in water and structurally related drugs from the sulfonamide family. The sensor showed very good reproducibility with the RSD at 0.48 %, repeatability and acceptable long term stability over a 10-day period. Good recovery from both tap and river water was achieved, with recovery ranging from 90.4 to 98.9 % for tap water and from 83.5 to 94.4 % for real river water samples. •A sensor for sulfonamides was developed using exfoliated MoS2 and reduced graphene oxide/graphite.•The reduced graphene oxide/graphite was superior to the pure reduced graphene oxide.•An impressive limit of detection of 86 nM was achieved for sulfonamide.•An extended linear range from 0.1 to 566 μM was obtained for sulfonamide.