1. A method for sensing a target object using optical mode excitations in microresonators, comprising: preparing at least one cluster including at least two microresonators; obtaining at least one first spectrum of the cluster; adsorbing the target object on a surface of the cluster; obtaining at least one second spectrum of the cluster; and sensing the target object by comparing a lineshape of the at least one first spectrum with a lineshape of the at least one second spectrum, wherein the at least one first spectrum is collectively obtained from the microresonators included in the cluster, and the at least one second spectrum is collectively obtained from the microresonators included in the cluster.