Dual-mode fluorescent probe for rapid lead detection in water and gasoline based on a perylene/β-cyclodextrin hybrid sensor

Lead is a toxic heavy metal utilized in various industrial applications, presenting considerable environmental and health hazards. Thus, its rapid detection is necessary in various industrial applications to prevent its toxic effecs. This study introduces a novel fluorescent probe utilizing perylene-3,4,9,10-tetracarboxylic diimide (PTCDI) modified with β-cyclodextrin (B_CD) to lead ion detection and mitigate the inherent hydrophobicity of PTCDI. B_CD is initially modified with aldehyde groups (B_CDA) and subsequently linked to PTCDI through the Schiff-base reaction to produce the final PI_CDA probe. The synthesis of PI_CDA is confirmed through Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies. Field emission scanning electron microscopy (FE-SEM) demonstrates distinct self-assembly structures, transitioning from clumped aggregates in B_CD to elongated cylindrical morphologies in PI_CDA, thereby underscoring the influence of chemical modification on nanostructure formation. The probe demonstrates enhanced fluorescence emission through the photoinduced electron transfer (PET) mechanism, facilitating the selective detection of lead ions while avoiding interference from other metal cations. The detection limit of this sensor for lead ions is determined 1.6 μM, with a maximum detection range of 55 μM. Furthermore, PI_CDA exhibits effective lead detection in gasoline, addressing a notable environmental issue.