[In ₃ O]-In Dual-Nodes-Based Metal–Organic Framework as a Self-Calibrating Luminescent Sensor for Rapidly Detecting Sophocarpine

Detection of sophocarpine, a pharmacologically active alkaloid with a narrow therapeutic window and potential neurotoxicity at elevated concentrations, is critically important in the clinic. In this work, we present an indium-based metal-organic framework {[(CH₃)₂(NH₂)][(In₃O)₂In₃(PPTA)₆(H₂O)₆]}_n (<b>1</b>) features with two kinds of In nodes and porous structure. This material as a self-calibrating luminescent sensor demonstrates high sensitivity in sophocarpine detection with a low detection limit of 7.1 × 10^-6 mol/L, excellent selectivity against interfering species, and good recyclability. Furthermore, a portable composite film (<b>1</b>@CRG) was fabricated, enabling instrument-free visual detection. This study establishes the first MOF-based platform for sophocarpine detection, providing a strategy for developing advanced sensor materials for clinical detection.