biostudies-literatureGong YSouth China Normal UniversityNational Natural Science Foundation of ChinaHigher Education Discipline Innovation ProjectMinistry of Education – Kingdom of Saudi Arabi30432-30438https://www.ebi.ac.uk/biostudies/studies/S-EPMC9073372biostudies-literatureUnknown9(52)In this study, a graphene-based composite 4HQ-rGO/Cu²⁺ was prepared <i>via</i> the supramolecular assembly of graphene nanosheets with 4-hydroxyquinoline (4HQ) and copper(ii) ions. The as-prepared supramolecular assembly exhibited an excellent and enhanced sensing performance towards acetic acid at room-temperature, which was due to the fact that the D-π-A molecules, <i>i.e.</i> 4HQ, were able to accelerate the charge transfer between the graphene nanosheets and 4HQ molecules when acetic acid was attached. In addition, at room temperature, the copper(ii) ions also played a critical role as the main active site for gas adsorption, and thus the as-fabricated sensor exhibited a high response, outstanding selectivity, and ultra-fast response/recovery time. To examine the selectivity of the Cu²⁺ ions for the supramolecular assembly, various other transition metal ions such as Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, and Cd²⁺ were attached to the 4HQ-rGO assembly, and their acetic sensing performance was determined. Interestingly, the supramolecular assembly with the Cu²⁺ ions (4HQ-rGO/Cu²⁺) exhibited the best sensing performance compared to other metal ion-based 4HQ-rGO materials. Compared with the typical acetic acid gas sensors reported in the literature, it is noteworthy to mention that the as-prepared 4HQ-rGO/Cu²⁺ supramolecular assembly exhibited the shortest gas response time (within 5 s) at room temperature. The presented study demonstrates that the as-prepared supramolecular assembly is a promising material as a room temperature acetic acid gas sensor in practical applications.RSC advancesAssembly with copper(ii) ions and D-π-A molecules on a graphene surface for ultra-fast acetic acid sensing at room temperature.PMC907337251973070PCSED-004-185177306951673007Li HUmar AAl-Assiri MSFan JFrans de Rooij NZhou GWang YGong YPei WfalseAssembly with copper(ii) ions and D-π-A molecules on a graphene surface for ultra-fast acetic acid sensing at room temperature.In this study, a graphene-based composite 4HQ-rGO/Cu²⁺ was prepared <i>via</i> the supramolecular assembly of graphene nanosheets with 4-hydroxyquinoline (4HQ) and copper(ii) ions. The as-prepared supramolecular assembly exhibited an excellent and enhanced sensing performance towards acetic acid at room-temperature, which was due to the fact that the D-π-A molecules, <i>i.e.</i> 4HQ, were able to accelerate the charge transfer between the graphene nanosheets and 4HQ molecules when acetic acid was attached. In addition, at room temperature, the copper(ii) ions also played a critical role as the main active site for gas adsorption, and thus the as-fabricated sensor exhibited a high response, outstanding selectivity, and ultra-fast response/recovery time. To examine the selectivity of the Cu²⁺ ions for the supramolecular assembly, various other transition metal ions such as Mn²⁺, Fe³⁺, Co²⁺, Ni²⁺, Cu²⁺, and Cd²⁺ were attached to the 4HQ-rGO assembly, and their acetic sensing performance was determined. Interestingly, the supramolecular assembly with the Cu²⁺ ions (4HQ-rGO/Cu²⁺) exhibited the best sensing performance compared to other metal ion-based 4HQ-rGO materials. Compared with the typical acetic acid gas sensors reported in the literature, it is noteworthy to mention that the as-prepared 4HQ-rGO/Cu²⁺ supramolecular assembly exhibited the shortest gas response time (within 5 s) at room temperature. The presented study demonstrates that the as-prepared supramolecular assembly is a promising material as a room temperature acetic acid gas sensor in practical applications.2019-01-01T00:00:00Z2019 Sep2025-04-04T23:17:22.859Z2025-04-04T23:17:22.859ZS-EPMC90733723553024110.1039/c9ra05706d