using static System.Console;

using System.Collections.Generic;

public class Program {

    public static void Main() => WriteLine(ToQueryString(new { nome = "Nome", valor = 10 }));

​

    public static string ToQueryString<T>(T model) {

        var query = new Dictionary<string, string>();

        foreach (var property in typeof(T).GetProperties())

            query.Add(property.Name, property.GetValue(model, null).ToString());

        return string.Join("&", query);

    }

}