Bacterial cellulose production from wastewater and the influence of its porosity on the fluorescence intensity of prepared carbon dots

Four kinds of bacterial cellulose (BC) were obtained by the stationary culture of Gluconacetobacter xylinus in molasses substitute medium, refined soybean oil wastewater, tofu product wastewater and barm washing effluent (BE) at 30 ℃ for 7 days, respectively. It was found that the BCs produced with different raw materials had differences in their porosity and compactness. The four kinds of BC were used to prepare carbon dots (CDs) using the hydrothermal method, respectively, confirming that the fluorescence intensity of the CDs was positively correlated with the porosity of the BC. Compared to other sources of BC, the BC produced from BE had the highest porosity at 72.57 % and the loosest structure; thus, the resultant CDs (CDs-BE) displayed the strongest fluorescence intensity and were rich in hydroxyl groups. To the best of our knowledge, this study is the first to examine the effect of raw material micromorphology on the fluorescence properties of CDs. CDs-BE displayed excellent performance in detecting Fe3+ ions with a detection range of 10–250 µM and a detection limit of 74 nM. This study realized the resource utilization of wastewater by fermenting G. xylinus to produce BC, and then prepared CDs with excellent fluorescence properties.