A Smartphone Assisted Portable Sensing Device for Turn‐on Fluorometric Detection of As ³⁺ Ion Using an AIE Active Quinazolinone Derivative

Abstract An AIE active molecule L1H bearing quinazolinone moiety was synthesized, thoroughly characterized and evaluated as a metal ion sensor. By virtue of having 4‐diethylaminophenyl group as fluorophore unit at the periphery, this probe exhibited a selective turn‐on response for As 3+ ion in aqueous HEPES and MeOH‐HEPES medium (6:4, v/v ), with a detection limit of 55 nM and 5.25 µM, respectively. The results of DFT/TDDFT calculations performed on L1H and [As( L1 )(Br 2 )] complex were consistent with the experimental findings. Practical application was demonstrated using portable, cost‐effective paper strips, and recovery tests were also conducted on various food and real water samples. Moreover, rapid on‐site detection of As 3 ⁺ ion was achieved using a prototype smartphone device. Molecular docking analysis of L1H with biomolecules such as BSA and HSA revealed binding affinities of −4.64, −7.12 kcal/mol, indicating their potential for albumin interaction and therapeutic use.