How to make physics collider sensor to false or true?

cocos2d-x JavaScript
#1 
cc.Class({
    extends: cc.Component,
    properties: {
    },
    onLoad () {
       this.physicsCircleCollider = this.node.getComponent(cc.PhysicsCircleCollider);
    },
    start () {
      // this.physicsCircleCollider.sensor = true; //Works here
        
    },
    update (dt) {
      this.physicsCircleCollider = true; //why it not works here?
    },
});

setting this.physicsCircleColider.senor = true works in onload() function but not works in update(dt){} function, any clue why or I’m missing something…