Ti 3 C 2 T x MXene with an organ-like structure was synthesized from Ti 3 AlC 2 (MAX phase) through the typical hydrofluoric (HF) acid etching method. Ti 3 C 2 T x MXene was further alkaline-treated with a sodium hydroxide solution to obtain alkalized Ti 3 C 2 T x . Room-temperature planar-type gas-and humidity-sensing devices were also fabricated by utilizing Ti 3 C 2 T x MXene and alkalized Ti 3 C 2 T x sensing material based on the dip coating method, respectively. The intercalation of the alkali metal ion (Na + ) and the increase of the surface terminal oxygen−fluorine ratio ([O]/[F]) in Ti 3 C 2 T x can effectively improve humidity-and gas-sensing properties at room temperature. The developed alkalized Ti 3 C 2 T x sensor exhibited excellent humidity-sensing characteristics (approximately 60 times response signal change) in the relative humidity (RH) with a range of 11−95% and considerable NH 3 sensing performance (28.87% response value to 100 ppm of NH 3 ) at room temperature. The improvement of NH 3 and humidity-sensing properties indicated that alkalized Ti 3 C 2 T x has great potential in chemical sensors, especially in NH 3 and humidity sensors. KEYWORDS: MXene, organ-like structure, alkalized Ti 3 C 2 T x , NH 3 and humidity sensing, room temperature

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Development of therapeutic vaccines/strategies to control chronic hepatitis B virus (HBV) infection (CHB) has been challenging due to HBV-induced tolerance. In this study, we explored strategies for breaking tolerance and restoring the immune response to the HBV surface antigen in tolerant mice. We demonstrated that immune tolerance status is attributed to the level and duration of circulating HBsAg in HBV carrier models. Removal of circulating HBsAg by a monoclonal anti-HBsAg antibody in tolerant mice could gradually reduce tolerance and reestablish B cell and CD4+ T cell responses to subsequent Engerix-B vaccination, producing protective IgG. Furthermore, HBsAg-specific CD8+ T cells induced by the addition of a TLR agonist, resulted in clearance of HBV in both serum and liver. Thus, generation of protective immunity can be achieved by clearing extracellular viral antigen with neutralizing antibodies followed by vaccination.