Chariwat PitsanuwongJuthamanee BoonwanSinchai ChomngamKanokorn WechakornPhongthon KanjanasiriratYongyut PewkliangSuparerk BorwornpinyoPalangpon KongsaereeSuan Sunandha Rajabhat UniversityRajamangala University of Technology Thanyaburi (RMUTT)Mahidol University2022-08-042022-08-042021-07-01Journal of Fluorescence. Vol.31, No.4 (2021), 1211-121815734994105305092-s2.0-85106730234https://repository.li.mahidol.ac.th/handle/20.500.14594/76126A highly selective rhodamine hydrazide-based fluorescent chemosensor for Au3+ detection was developed. The aqueous solution of rhodamine N-hydroxysemicarbazide (RHS), in the presence of Au3+, exhibited a significant 55-fold turn-on fluorescence response at 591 nm and a colorimetric change from colorless to pink. Other interested ions including Li+, Na+, K+, Cs+, Mg2+, Ca2+, Ba2+, Pb2+, Mn2+, Co2+, Ni2+, Ag+, Cd2+, Cu2+, Hg2+, Zn2+, Sn2+, Fe2+, Fe3+, Cr3+, Ce3+ did not induce any distinct color/spectral changes. The irreversible detection mechanism occurred via Au3+-promoted 5-exo-trig ring closure to yield 1,3,4-oxadiazole-2-one product. The RHS probe is non-responsive to other biologically relevant metal ions and the limit of detection for Au3+ was calculated to be 0.5 µM with a linear range of 0 to 90 µM. Fluorescence bioimaging of Au3+ in HepG2 cells was also successfully demonstrated.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemistryArticleSCOPUS10.1007/s10895-021-02725-0