A novel electrostatic drive strategy to prepare glutathione-capped gold nanoclusters embedded quaternized cellulose membranes fluorescent colorimetric sensor for Pb(II) and Hg(II) ions detection

It is necessary to establish a fast and accurate sensor strip for detecting Pb(II) and Hg(II) ions in water. Herein, a novel electrostatic drive strategy to prepare glutathione-capped gold nanoclusters embedded quaternized cellulose membranes fluorescent colorimetric sensor (GSH-AuNCs@QCM) for efficient detection of Pb(II) and Hg(II) ions in water has been designed. GSH-AuNCs were synthesized as fluorescent probes by thermal reduction. Quaternized cellulose membrane (QCM) was prepared by the casting method after grafting modification of cellulose. GSH-AuNCs@QCM was prepared by electrostatically driven GSH-AuNCs embedded in QCM. The structure and properties of GSH-AuNCs@QCM were tested in terms of SEM, FTIR, BET, and XPS. Besides, the preparation and detection mechanisms of GSH-AuNCs@QCM were also explored. The detection ranges of Pb(II) and Hg(II) were both located within 5 × 10−6 ~ 5 × 10−3 mol/L, where the minimum detection concentrations of Pb(II) and Hg(II) at which color changes could be visually observed were both 5 × 10−6 mol/L, and the response time was 2 min. The sensor has been successfully used in the detection of actual water samples. Moreover, the sensor was reused after EDTA processing. Hence, this work provided a novel electrostatically driven method to prepare cellulose membrane-based sensors as a bimetal detection platform, which has great potential in the early diagnosis of environmental water samples and contributes to the development of high-performance and multifunctional cellulose-based sensors in the future. [Display omitted] •A novel electrostatic drive strategy to prepare GSH-AuNCs embedded QCM.•GSH-AuNCs@QCM was used as a fluorescent probe to detect Pb(II) and Hg(II).•The minimum detection limit was 5 μM for both Pb(II) and Hg(II) with the naked eye.•The GSH-AuNCs@QCM has been successfully used in the detection of actual water samples.•The used GSH-AuNCs@QCM sensor can be recovered by EDTA and can be reused.