Unclosed quotation mark after the character string ',', ')'. Incorrect syntax near ',', ')'

Can you help me correct this detail please

       public void crear(Alumno objAlumno)
    {
        string crear = "insert into Persona(idAlumno,nombre,Apellido,Telefono)values('" + objAlumno.IdAlumno + "'," + objAlumno.Nombre + "','" + objAlumno.Apellido1 + "','" + objAlumno.Telefono1 + "')";
        try
        {
            conn = new SqlCommand(crear, objConexion.getcon());
            objConexion.getcon().Open();
            conn.ExecuteNonQuery();
        }
        catch (Exception)
        {

            throw;
        }
        finally
        {
            objConexion.getcon().Close();
            objConexion.cerrarConexion();

        }
    }