Green Preparation of Mn‐Doped ZnS Quantum Dots/Gelatin Composite Gel Beads and Their Applications in Detection

Abstract

AbstractHerein, Mn‐doped ZnS quantum dots/gelatin (QDs‐G) composite gel beads were directly prepared by a green and novel method. The method shows a range of benefits, such as the green and convenient process, mild conditions, and simple post‐processing. The resulting QDs‐G gel beads are transparent, homogeneous and stable. These gel beads exhibit clear orange‐red fluorescence under 302 nm UV light, which is associated with Mn‐doped ZnS QDs. Additionally, the QDs‐G gel beads possess a reversible thermo‐responsive sol‐gel transition property. TEM observation shows that there are QDs in the QDs‐G gel beads, and their average particle size is 4.0 nm. The QDs‐G gel beads can be innovatively used for both fluorescent detection and colorimetric detection, which show advantages such as simple operation, direct observation (no need for instruments), wide detection range, and good anti‐interference ability. Moreover, the more accurate fluorescence detection toward Cu2+ can be conducted through QDs/gelatin solution (the detection limit is 0.16 μM) based on the thermo‐responsive sol‐gel transition property of the gel beads. Therefore, the as‐fabricated QDs‐G gel bead is a promising candidate for application in the detection field.