One kind of union biosensor technology and isolation technique, From natural medicine, selection and separation have the combination PBP2a active method of organizing minute or active material, the method will PBP2a coating on the sample pool biosensor match as a solid base to extract natural medicines the mobile phase of the selected combination with PBP2a in the role of natural medicine, will be an integrated component of the higher value after isolation and purification, has been a collaborative antagonistic MRSA activity combined with PBP2a occurred role of the active component, the Preparation synergistic components can be used to beta - lactam antibiotics treatment of MRSA infection drugs or lead compounds. This method has time-saving, the high flux, to reduce effort, the specificity to be strong, the result accurate, can real-time monitoring many kinds of merits.