How can I do to use the masterdetail that already has?

explain:
what happens is that use notifications and at the moment of giving click to the notification, leads me to a page that I told you, but does not use the masterdetailPage that I already had before, creates a new one apparently... shows me the menu but when clicking any of the options nothing happens, does anyone know how to solve this?

Im use for open :
((InicioPage)Xamarin.Forms.Application.Current.MainPage).Detail = new NavigationPage(new PaginaDatos());

Thanks in advance.