Lignin-Based CdS Dots


    In News

    • Recently, a research team from the DBT-CIAB (Centre of Innovative and Applied Bioprocessing), Mohali, has developed an antimicrobial coating from agricultural waste called L@CdS QDs (quantum dots)

    About L@CdS QDs

    • Lignin is is a complex, woody biopolymer that gives mechanical support to plants and helps transport water and nutrients.
      • Post-harvest, lignin is left over as stubble, either burnt or used as cattle feed.
    • Lignin is rich in carbon, polyphenols, and antioxidants besides having antimicrobial properties.
    • Green method: The team has used green methods to synthesise extremely tiny particles of cadmium sulphide, an inorganic compound with lignin forming the matrix for the material.
      • Cadmium sulphide nanoparticles absorb light energy and shift to a high-energy excited state. In this state, they react with ambient oxygen molecules and transfer the absorbed energy to them.
    • Mechanism: The researchers used kraft lignin for the base material. To obtain the QDs, they added a one-step chemical process to the lignin and incubated the mixture under 365 nm UV light for 24 hours.
      • The test results revealed that the nanocomposite L@CdS QDs absorbs energy photons from ambient light and generates reactive oxygen species.
    • Glow: When UV light falls on the nanocomposite, it glows with a cyan-blue colour. However, when they interact with bacteria, the glow vanishes. 

    Source: DTE