  The Hamiltonian constraint of scalar-tensor theories in the Jordan frame is
quantised using three quantisation prescriptions in loop quantum cosmology,
from which we obtain three different effective Hamiltonian constraints. The
corresponding effective equations of motion derived from these effective
Hamiltonian constraints turn out to be drastically different. The implications
of each set of effective equations of motion are discussed in detail. In the
latter half of this paper, as a concrete example, we study the effective
dynamics of a specific model with the non-minimal coupling function
$F(\phi)=1+\xi\kappa\phi^2$ and self-interacting quartic potential. Using
numerical results, we find different features for different effective dynamics.
Moreover, it is also found that the spacetime singularity is absent and the
cosmological bounce exists in each effective dynamics of this model.
