In order to search for a gas sensor to detect hydrogen fluoride (HF), the adsorption of HF on transition metal-embedded graphene (TM/graphene) is investigated by density functional theory calculations. Compared with the relatively weak adsorption on other TM/graphene systems, HF molecule tends to be adsorbed on Ti/graphene with appreciable adsorption energy. Based on these calculations, two gas sensing mechanisms are proposed and revealed that both surface reconstruction and charge transfer result in a change of electronic conductance of Ti/graphene. Thus, this developed Ti/graphene would be an excellent candidate for sensing HF with lower cost and higher activity. (C) 2013 Elsevier B.V. All rights reserved.