VIS/NIR double-domain luminescence sensing with anti-interference performance by a lanthanide-organic framework nanosheet loaded with atomically dispersed Cu sites

Fluorescence/luminescence detection has garnered extensive attention due to its remarkable sensitivity and selectivity within the visible (VIS) and near-infrared (NIR) spectrum. However, detection in the VIS domain is susceptible to interference from background fluorescence and internal quenching effects; the reliability and stability of NIR detection are constrained by its luminescence efficiency and lifetime. In this context, we introduce a dual-domain detection strategy under both VIS and NIR illumination, leveraging the advantages of both domains to achieve anti-interference luminescence detection of tetracycline hydrochloride (TC). Specifically, Cu2+ ions were incorporated into Yb-TCPP nanosheets (H2TCPP = 5,10,15,20-tetra-(4-carboxyphenyl) porphyrin) and anchored at the porphyrin core of the TCPP2- ligand, forming highly dispersed Cu-N4 sites. Notably, the Cu@MOF luminescent material exhibited a picomolar level dual-domain fluorescence/luminescence response towards TC: it activates detection in the VIS domain and turns off in the NIR domain. Largely due to this dual-domain response, the sensor showcases excellent anti-interference capabilities and reliability. When the VIS domain is perturbed, the sensor's detection in the NIR domain remains unaffected; conversely, interference in the NIR domain barely impacts the sensor's behavior in the VIS domain. Furthermore, a systematic mechanistic analysis suggests that the introduction of atomically dispersed Cu2+ sites not only enhances the acid-base interaction sites between the sensor and the analyte but also amplifies the adsorption capacity towards the analyte, effectively reducing detection limits and bolstering anti-interference capabilities. Anticipating the future, this detection strategy holds promise in offering a more cost-effective, reliable, and interference-resistant option for commercial detection, signaling a bright prospect for its development.