Hydrothermal Synthesis of Fluorescent Functionalized MoS₂ Quantum Dots for Heavy Metal Detection

Autor(es)

Schneider, Rodrigo ; Facure, Murilo H. M. ; Teodoro, Kelcilene B. R. ; Mercante, Luiza A. ; Correa, Daniel S.

• Tipo de documento: Artigo Científico
• Fonte: ACS APPLIED NANO MATERIALS; v. 6, n. 23, p. 11-pg., 2023-11-20.

Resumo

Surface functional groups of molybdenum disulfide (MoS2) quantum dots (QDs) can play a fundamental role in their optical properties. Nonetheless, the use of fluorescent MoS2 QDs as optical probes still requires further investigation regarding their surface properties and functional groups. Because such features depend on the synthesis procedures employed, which influence the nanomaterials' morphologies and structure, it becomes essential to understand the influences of the synthesis parameters on the material properties. Here, we demonstrate how to tune the surface properties of MoS2 QDs by alterations in the synthesis parameters and how they influence the copper ions (Cu2+) detection. Different stoichiometric ratio (Mo:S) between sodium molybdate:l-cysteine and reaction times of 7 or 17 h were used on the syntheses of MoS2 QDs, resulting in changes in the amount of partially oxidized functional groups (SO3/SO3H/SO42-/S2O22-) and oxygen functionalities (Mo-O/Mo=O/-COOH), according to Fourier transformed infrared and X-ray photoelectron spectroscopies analyses. The results show that the partially oxidized functionalization and sulfur-based groups of MoS2 QDs were obtained and led to remarkable changes in the photoluminescence (PL) properties, with quantum yields ranging from 7.0 to 13.1%. At the optimal synthesis condition, the MoS2 QDs could detect Cu2+ in water with a limit of detection (LoD) as low as 0.07 mu M. Additionally, the MoS2 QDs obtained demonstrated the ability to discriminate Cu2+ from other common metal ions by using Principal Component Analysis (PCA). The sensing performance was attributed to the surface functional group tuning, which can be tailored by the synthesis parameters to enhance the LoD, quantum yield, or affinities toward different heavy metals. (AU)

• Processo FAPESP: 18/18468-2 - Metodologias de sínteses de nanoestruturas de dissulfeto de molibdênio (MoS2) e avaliação da sua potencial aplicação em sistemas de adsorção de poluentes
• Beneficiário: Rodrigo Schneider
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 17/10582-8 - Produção e caracterização de quantum dots de grafeno e sua aplicação em sensores químicos
• Beneficiário: Murilo Henrique Moreira Facure
• Modalidade de apoio: Bolsas no Brasil - Doutorado
• Processo FAPESP: 18/22214-6 - Rumo à convergência de tecnologias: de sensores e biossensores à visualização de informação e aprendizado de máquina para análise de dados em diagnóstico clínico
• Beneficiário: Osvaldo Novais de Oliveira Junior
• Modalidade de apoio: Auxílio à Pesquisa - Temático