Fig. 7

Time-dependent frequency changes of the circulating-flow QCM sensor, (a) addition of Probe 1 (1 μM; P1-30/12 T) for immobilization on the surface of the QCM sensor via self-assembly, (b) complementary target oligonucleotides [0.5 μM; T-104(AS)] are subsequently introduced for DNA hybridization, (c) additional treatment of the DNA hybridized QCM with Probe 2 (P2-30/12 T)-capped Au nanoparticles. The sequences of Probe 1 and Probe 2 are complementary to the two ends of the analyte DNA (i.e., target sequences) (Reproduced from Chen et al. [72] with permission from Elsevier)