Interfacial Synthesis of Prussian Blue-Decorated Sulfur-Doped Reduced Graphene Oxide Nanocomposite for Electrochemical Sensing and Detoxification of As(III)

• Published in: ACS applied nano materials Vol. 6; no. 20; pp. 19218 - 19229
• Main Authors: Wani, Adil Amin, Jan, Qounsar, Bhat, Murtaza Manzoor, Kuchey, Mohammad Yaseen, Sofi, Feroz Ahmad, Shah, Rameez A, Bhat, Sami Ullah, Bhat, Aamir Y., Ingole, Pravin P., Bhat, Mohsin Ahmad
• Format: Journal Article
• Language: English
• Published: American Chemical Society 27.10.2023
• Subjects: sulfur-doped reduced graphene oxide; Prussian blue; electrochemical sensor; interfacial synthesis; arsenite
• ISSN: 2574-0970; 2574-0970
• DOI: 10.1021/acsanm.3c03639

Electrochemical sensing is considered as one of the most promising approaches for quick, reliable, and on-site detection and monitoring of arsenic (As) levels in water. However, the unavailability of stable, selective, and affordable electrode materials hampers the development of portable, cost-effective, reliable, and practically applicable arsenic-sensing electrochemical devices. In this article, we describe a straightforward biphasic synthesis method for the crafting of sulfur-doped reduced graphene oxide (S-rGO)-supported Prussian blue (PB) nanodeposits (S-rGO/PB), a nanocomposite with exceptional stability and activity for selective and sensitive electrochemical sensing of As. The S-rGO/PB is demonstrated to selectively and sensitively electrocatalyze the As(0)/As­(III) and As­(III)/As­(V) charge transfer processes via the participation of the Fe­(II)/Fe­(III) cycle as revealed by X-ray photoelectron spectroscopy, thereby ensuring accurate and sensitive electrochemical sensing of As in water samples. We demonstrate that with the S-rGO/PB electrode, As­(III) can be sensed via differential pulse voltammetry (DPV) with sensitivity values of 1.79 (As(0)–As­(III)) and 10.69 μA ppb–1 cm–2 (As­(III)–As­(V)) and limits of detection as low as 0.0104 and 0.0536 ppb, respectively. Alongside real-time applicability, the S-rGO/PB is demonstrated to exhibit excellent stability and specificity toward arsenic sensing even in the presence of other interferents. Importantly, the As­(III) estimates obtained for real water samples using DPV over S-rGO/PB closely match the estimates obtained with atomic absorption spectrometry, a highly expensive and sophisticated state-of-the-art technique known for its accuracy in estimation of the sub-ppb traces of heavy metals. The presented results suggest that the S-rGO/PB composite is a promising electrode material that can facilitate the design and development of portable, affordable, reliable, and practically applicable electrochemical setups for on-site sensing and electrodetoxification of As­(III) in water samples. The availability and accessibility of such setups are a must for the worldwide success of arsenic mitigation initiatives, particularly in underdeveloped and impoverished nations.