Single transition operators are adapted to simplify the density matrix theory for the spin dynamics calculation of quadrupole nuclei with more than one spin transition in zero field. We employ the formalism on the spin I=5/2 system with axial symmetry to obtain the responses of multiple pulses for nuclear quadrupole resonance regardless the spin relaxation. The theoretical calculation for pulse response is illustrated from one-pulse to multipulse and one-dimension to multidimension explicitly. Subsequently sensitivity-enhanced nuclear quadrupole correlation spectroscopy (SENQCOSY) is proposed and demonstrated. Experimental results are compared with conventional nuclear quadrupole correlation spectroscopy (NQCOSY) for Sb-121 (I=5/2) in SbCl3 system. The maximum sensitivity is enhanced by a factor of 2.66, which are in good agreement with theoretical prediction.