•A new furfuran-based rhodamine B fluorescent probe (RBFF) was designed and synthesized.•RBFF exhibits a highly sensitive and selective “turn-on” fluorescent response to Fe3+ and “turn-off” response to B4O72−.•The detection limit of RBFF for Fe3+ was calculated to be 0.025 μM.•Cell studies demonstrated that RBFF can serve as a biological fluorescence probe for the detection of Fe3+ in HeLa cells.A new furfuran-based rhodamine B fluorescent probe (RBFF) has been designed and synthesized, and its sensing behavior towards various metal ions was evaluated via UV–vis and fluorescence spectroscopic techniques. RBFF exhibits a highly sensitive and selective “turn-on” fluorescent response toward Fe3+ ion and a fluorescence “turn-off” response when added B4O72− to the RBFF-Fe3+ in the EtOH/H2O solution (1:1, v/v, HEPES, 1 mM, pH 7.20). The detection limit of RBFF for Fe3+ was calculated to be 0.025 μM. The fluorescence microscopy experiment suggested that RBFF could also be served as a biological fluorescence probe for the detection of Fe3+ in human cervical carcinoma cells (HeLa).Download high-res image (96KB)Download full-size image