Blue-emitting CdSe/ZnS quantum dots require precise control of crystal growth because variations in particle size and surface structure can strongly influence their emission properties. In this study, blue-optical CdSe/ZnS core–shell quantum dots were synthesized using a one-step hot-injection method. Structural and optical characterization confirmed the formation of crystalline QDs with stable fluorescence emission after ZnS shell coating. The synthesized QDs exhibited an average diameter of approximately 3 nm, blue emission at 461 nm, and a photoluminescence quantum yield of 93.31%. The QDs exhibited suitable optical properties for fluorescence-based bioanalytical applications for HCG.

The high infectivity, difficulty to diagnose, and high drug resistance of melioidosis limited the timeliness of treatment. Lateral flow assay (LFA) was operated in this research to provide an instant diagnosis method, and a fast antibody rapid matching test strategy based on LFA was developed to select the most sensitive and specific pair of antibodies. Compared to the traditional ELISA method, the new matching strategy limits the pairing time to 3 h without any complex instruments. The rapid pairing test strategy is a universal strategy that is suitable for various sandwich immune antigen pairings. To fasten the test of the test strips, dry fluorescence immunoassay analyzer (DFIA) was designed and applied. The equipment also simplifies the process of data acquisition. Finally, the concentration gradient test was operated, and the detection lines and limits were presented.