Rima Heider Al Omari, Shelesh Krishna Saraswat, Abhinav Kumar, Subbulakshmi Ganesan, Shaker Mohammed, Aashna Sinha, Hadi Noorizadeh and Mosstafa Kazemi
{"title":"Nanoconfined MoS2 quantum dots in mesoporous TiO2: a high-performance platform for electrochemical microplastic sensing","authors":"Rima Heider Al Omari, Shelesh Krishna Saraswat, Abhinav Kumar, Subbulakshmi Ganesan, Shaker Mohammed, Aashna Sinha, Hadi Noorizadeh and Mosstafa Kazemi","doi":"10.1039/D5EW00454C","DOIUrl":null,"url":null,"abstract":"<p >The increasing prevalence of microplastic pollution in aquatic environments necessitates the development of sensitive, selective, and rapid detection platforms. Herein, we report the fabrication of a high-performance electrochemical sensor based on nanoconfined MoS<small><sub>2</sub></small> quantum dots (QDs) integrated into a mesoporous TiO<small><sub>2</sub></small> matrix. The hybrid nanocomposite was synthesized <em>via</em> a template-assisted sol–gel strategy, ensuring uniform dispersion and confinement of MoS<small><sub>2</sub></small> QDs (3–6 nm) within TiO<small><sub>2</sub></small> mesopores (∼3.5 nm). Structural and morphological analyses confirmed the formation of a highly porous, crystalline framework with preserved mesostructure and enhanced surface area. Electrochemical characterization demonstrated significantly improved redox activity and charge transfer kinetics due to synergistic interactions between the quantum-confined MoS<small><sub>2</sub></small> domains and the conductive TiO<small><sub>2</sub></small> scaffold. The modified glassy carbon electrodes exhibited excellent sensitivity toward polystyrene (PS) and polypropylene (PP) microplastics across a wide dynamic range (10<small><sup>4</sup></small>–10<small><sup>10</sup></small> particles per mL), with a limit of detection of 5.0 × 10<small><sup>3</sup></small> particles per mL. The sensor showed strong selectivity against various ionic and organic interferents, and maintained high analytical performance in complex matrices including seawater, tap water, and simulated environmental samples. Reproducibility and long-term stability were also validated under varying storage conditions. These results highlight the promise of the MoS<small><sub>2</sub></small> QD/TiO<small><sub>2</sub></small> nanoplatform as a scalable and robust electrochemical system for real-time monitoring of microplastic contaminants in environmental waters.</p>","PeriodicalId":75,"journal":{"name":"Environmental Science: Water Research & Technology","volume":" 9","pages":" 2192-2210"},"PeriodicalIF":3.1000,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Science: Water Research & Technology","FirstCategoryId":"93","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2025/ew/d5ew00454c","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, ENVIRONMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
The increasing prevalence of microplastic pollution in aquatic environments necessitates the development of sensitive, selective, and rapid detection platforms. Herein, we report the fabrication of a high-performance electrochemical sensor based on nanoconfined MoS2 quantum dots (QDs) integrated into a mesoporous TiO2 matrix. The hybrid nanocomposite was synthesized via a template-assisted sol–gel strategy, ensuring uniform dispersion and confinement of MoS2 QDs (3–6 nm) within TiO2 mesopores (∼3.5 nm). Structural and morphological analyses confirmed the formation of a highly porous, crystalline framework with preserved mesostructure and enhanced surface area. Electrochemical characterization demonstrated significantly improved redox activity and charge transfer kinetics due to synergistic interactions between the quantum-confined MoS2 domains and the conductive TiO2 scaffold. The modified glassy carbon electrodes exhibited excellent sensitivity toward polystyrene (PS) and polypropylene (PP) microplastics across a wide dynamic range (104–1010 particles per mL), with a limit of detection of 5.0 × 103 particles per mL. The sensor showed strong selectivity against various ionic and organic interferents, and maintained high analytical performance in complex matrices including seawater, tap water, and simulated environmental samples. Reproducibility and long-term stability were also validated under varying storage conditions. These results highlight the promise of the MoS2 QD/TiO2 nanoplatform as a scalable and robust electrochemical system for real-time monitoring of microplastic contaminants in environmental waters.
期刊介绍:
Environmental Science: Water Research & Technology seeks to showcase high quality research about fundamental science, innovative technologies, and management practices that promote sustainable water.