Dipicolinate (DPA) is a biomarker for Bacillus anthracis spores. In this effort, an optical sensing composite with two sensing channels for the detection of dipicolinate (DPA) was reported. This composite material was constructed using luminescent metal-organic framework (MOF) as supporting substrate and a rhodamine-liked dye as sensing probe, respectively. By means of electron microscopy images, XRD, IR, TGA, absorption and emission spectra, this composite sample was characterized carefully. It was found that there were two sensing channels for DPA, including colorimetric sensing and ratiometric fluorescent sensing. Linear sensing response was observed for both sensing channels. LOD value was as low as 4.5 μM with good selectivity. Corresponding sensing mechanism was revealed as a rhodamine structural transformation initiated by DPA released protons and an emission quenching caused by energy transfer from Eu(BTC) to DPA (pyridine ring). This composite material showed a superior sensing performance in virtue of its dual sensing channels and the possibility of naked eye detection.

Dipicolinate（DPA）是炭疽芽孢杆菌孢子的生物标记。在这种努力中，报告了具有两个传感通道的光学传感复合材料，用于检测吡啶二甲酸酯（DPA）。该复合材料分别使用发光金属有机骨架（MOF）作为支撑基材和类若丹明样染料作为传感探针构建。通过电子显微镜图像，XRD，IR，TGA，吸收和发射光谱，对该复合样品进行了仔细表征。发现DPA有两个感应通道，包括比色感应和比率荧光感应。对于两个感测通道均观察到线性感测响应。LOD值低至4.5μM，具有良好的选择性。相应的传感机制被揭示为由DPA释放的质子引发的罗丹明结构转变和能量从Eu（BTC）转移到DPA（吡啶环）引起的发射猝灭。这种复合材料凭借其双重感测通道和裸眼检测的可能性显示出卓越的感测性能。