The rate of tetracycline (TC) production and consumption has tremendously increased lately for the treatment of infectious diseases in humans and animals. Their release into the environment through overuse and improper disposal practices has raised serious concerns for the ecosystem deliberating the significance of easy detection approaches towards TC. By virtue of the excellent physical and chemical attributes of Metal-Organic frameworks (MOFs), a Tb-doped MOF was developed for the selective and accurate detection of TC. Remarkably, the strong green luminescence of Tb3+ is quenched efficiently with TC even in the presence of other antibiotics. The sensor material exhibits a highly sensitive turn-off response with an exceptionally low limit of detection of 0.07 μM and a quenching constant value of 1.68 × 104 M-1. The mechanisms for selective quenching of fluorescence towards TC are investigated in detail using theoretical calculations and simulations to demonstrate the occurrence of electron transfer within the system. The detection behavior is also tested with river water samples collected from Chennai rivers which exhibited an excellent recovery of results qualifying Tb@ZB as a promising candidate to be developed into a prototype device to enable facile rapid analysis in real-time samples. The sensing approach provides a crucial ground for monitoring the presence of TC with 87–101 % reliability in wastewater systems.