Preparation of Quantum Dots (QDs) Nanobeads for QDNB-Based Lateral Flow Immunoassay

To begin, mix 0.4 milliliters of polystyrene co-maleic anhydride solution and 0.1 milliliters of QD solution to prepare 1 milliliter of the oil phase. Then fill the rest with chloroform until the volume reaches 1 milliliter. Next, prepare the aqueous phase using sodium dodecyl sulfate solution.

Combine 1 milliliter of the oil phase and 5 milliliters of the aqueous phase in a vial. Place the vial on a magnetic stir and turn it on. Once the oil and aqueous phases are thoroughly mixed, immediately transfer the vial to the programmed ultrasonication device and turn on the power.

Then place the vial back on the magnetic stir at room temperature and stir continuously overnight. After solvent evaporation, add 0.1 milliliters of 0.1 millimolar sodium hydroxide to the nanobead suspension, and allow it to react for one hour.