Angular – DevExpress dxdatagrid disable checkbox conditionally

I am trying to disable checkbox of my dxdatagrid on certain condition. But it does not seems to be working. Below is my code :-

 onCellPrepared(event: any)
{
    console.log(event.rowType);
    if (event.rowType === "data")
     {
      debugger;
      var instance = event.cellElement.find('.dx-select-checkbox').dxCheckBox("instance");
      instance.option("disabled", true);
      event.cellElement.off();
    }
  }

Below is the error i get on execution :-

ERROR TypeError: event.cellElement.find is not a function

Please advise.