Discriminative Sensing of Structurally Similar Neurotransmitters via In-TBAPy MOF Arrays

The accurate discrimination of structurally analogous neurotransmitters remains a formidable challenge due to their high structural similarity and overlapping chemical properties. To address the limitations of low specificity in single-probe sensors and the fabrication complexity of multi-component arrays, we developed a simplified fluorescence sensing array based on a single pyrene-functionalized MOF, In-TBAPy. This strategy leverages the distinctive monomer-to-excimer luminescence transition of In-TBAPy, triggered by the tunable π-π stacking of pyrene units within the crystalline framework. The results demonstrate that the array, integrated with Linear Discriminant Analysis (LDA) across four optimized emission channels, achieves a classification accuracy of 93.75% in identifying four highly similar neurotransmitters: serotonin (5-HT), dopamine (DA), adrenaline (A), and norepinephrine (NA). Notably, the sensing platform exhibits exceptional robustness in simulated physiological environments and complex multi-analyte mixtures, enabling reliable quantitative analysis: 0-100 μM for 5-HT and adrenaline (A), 0-40 μM for dopamine (DA), and 0-80 μM for norepinephrine. Mechanistic studies suggest that the differential quenching of monomer and excimer peaks stems from the synergistic effect of competitive absorption and host-guest interactions. This work effectively overcomes the cross-interference issues of traditional sensors and validates a high-efficiency solution for high-throughput neurotransmitter analysis using a single-material-based array strategy, significantly reducing operational costs and preparation time.