Multiplexed bio-imaging using cadmium telluride quantum dots synthesized by mathematically derived process parameters in a continuous flow active microreactor

Quantum dots (QDs) are semiconductor nanocrystals with unique size-tunable emissions. To obtain a precise emission spectrum, monodispersity in size is imperative, which is achieved by controlling the reaction kinetics in a continuous flow of active microreactors. Further, a multivariate approach (dimensional analysis) is employed to impose stringent control on the reaction process resulting in monodispersed preparation of cadmium telluride (CdTe) quantum dots. Dimensional analysis knits multiple variables into a dimensionless mathematical form which not only predicts parameters precisely to obtain narrow size tunability but also guarantees reproducibility in synthesis. Analytical, structural, and optical characterization of the microreactor synthesized poly-dimethylsiloxane (PDMS) coated CdTe QDs reveal quantum efficient (61.5%), photostable (44%), and biocom-patible nanocrystals of 5-15 nm. Further, PDMS-coated QDs (P-QDs) are conjugated with organelle-specific antibodies/biomarkers for in-vitro imaging in NIH 3T3 cells. Likewise, proliferating cell nuclear antigen (PCNA) and anti-myosin (MF20), cardiomyocytes antibodies are conjugated with P-QDs (red and green, respec-tively) to image the zebrafish's cardiac tissue. Antibodies tagged with quantum dots are imaged simultaneously using confocal microscopy. Thus, multiplexed bio-imaging of in-vitro and zebrafish tissue is demonstrated suc-cessfully. The results indicate the suitability of continuous flow active microreactor in conjunction with the mathematical prediction of process parameters to synthesize reproducibly monodispersed and quantum efficient QDs.