Fig. 5.

RCA-QCM biosensor: (a) hybridisation of a circular probe with a target strand results in the circularisation and ligation of the probe, whereas RCA does not occur for a single-mismatch strand. The RCA product then binds to the crystal surface via the complementary capture probes; (b) real-time frequency response of the biosensor during the RCA reaction; (c) frequency shifts of the biosensor (with and without RCA reaction) in response to the negative control, HBV DNA target, and single-mismatch strand. Reprinted with permission from Yao et al. (2013).