Escape special characters from JSON string

I am returning a JSON string via AJAX call and then passing it to the browser, however, it breaks when there are special characters in the string.

Is there a function that can remove special characters from JSON string.

Here is my code:

var stdepartmentJSON = ajaxGetDepartment(ID);
var jsonDept = jQuery.parseJSON(stdepartmentJSON);

I am using ColdFusion as the server side language. Tried using JSStringFormat(), but it doesn't work