Thank you Dr.Michele Carboni.. We have already prepared Au@SnO2 material by using ur refered paper of Mulveny in our lab for gas sensor application. It was Au Nps. but I want to coat SnO2 on Au nanorod. In Au nanorods the surafce has CTABs ..so it is not easily geting coated SnO2..so many time tried but not success.