Checkbox not getting disabled using jquery

I am facing a weird issue. I am not able to access the checkbox to be disabled using jquery. Here is the code snippet:

HTML

<td class="checkbox1 col5">
    <input type="checkBox" 
           class="checkbox " 
           ng-click=" massUpdateMainCtrl.offboardContractor(contractorInfo,$index)" 
           id="" 
           ng-disabled="massUpdateMainCtrl.disableCheckBoxAlreadyAddedToMassUpdate()" 
           ng-checked="massUpdateMainCtrl.disableCheckBoxAlreadyAddedToMassUpdate()"> 
    <label for=""></label>
</td>

CSS

   input[type=checkbox] {
       display: none;
}

       .checkbox1 label {
        border: 1px solid #c0c0c0;
        height: 15px;
        width: 15px;
        max-width: 100%;
        margin-bottom: 0px;
        font-weight: bold;
        vertical-align: middle!important;

}

JQuery:

$(".checkbox").attr('disabled', 'disabled');

Problem here is I am not able to disable the checkbox using jquery.

Please help.