How to add an attribute in class for each element

[DataContract]
   public class Applicant
   {
       private string titleField;
       private string firstNamesField;

       [DataMember(Order = 1)]
       public string Title
       {
           get
           {
               return this.titleField;
           }
           set
           {
               this.titleField = value;
           }
       }
       [DataMember(Order = 2)]
       public string FirstNames
       {
           get
           {
               return this.firstNamesField;
           }
           set
           {
               this.firstNamesField = value;
           }
       }
   }

var app = new Applicant();
var dcs = new DataContractSerializer(app.GetType());
           var ms = new MemoryStream();
           dcs.WriteObject(ms, app);
           string xml = Encoding.UTF8.GetString(ms.GetBuffer(), 0, (int)ms.Position);
           var doc = XElement.Parse(xml);

<Applicant xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/testApp">
		<Applicant>
			<Title>Mr</Title>
			<FirstNames>Applicant</FirstNames> 
		</Applicant>
	</Applicant>

<Applicant xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/testApp">
		<Applicant>
			<Title IsEnabled="True">Mr</Title>
			<FirstNames IsEnabled="True">Applicant</FirstNames>
		</Applicant>
	</Applicant>