MaterializeCSS dropdown with Ionic not working

I'm developing an Ionic mobile app with Materialize CSS. The problem is when I have to add components like dropdown menu.

 <!-- Dropdown Trigger -->
  <a class='dropdown-button btn' href='#' data-activates='dropdown1'>Drop Me!</a>

  <!-- Dropdown Structure -->
  <ul id='dropdown1' class='dropdown-content'>
    <li><a href="#!">one</a></li>
    <li><a href="#!">two</a></li>
    <li class="divider"></li>
    <li><a href="#!">three</a></li>
  </ul>

The problem is href in dropdown-button, which redirect to a Route which address # instead of showing the menu.

How can I make working this component?

Thanks