Fig. 1

Schematic diagram of QD-based ICTS. a Conjugation of CdSe/ZnS QDs with CA72-4 mAb (CC49). b Structure of QD-based ICTS. c Sample containing CA72-4 was dropped to sample pad and migrated along the ICTS. Firstly, CA72-4 in the samples combined with QDs probeat conjugate pad. The formed complexes continued to migrate along the membrane and were captured by B72.3 on test line and formed QD-labeled CC49-CA72-4–B72.3 complexes. As the liquid sample continued migrating, the residual CC49 was captured by the goat anti-mouse IgG immobilized on control line. The excess QD conjugates continued to migrate towards the absorbent pad