Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, 381 Wushan Road, Guangzhou, 510641, China.
Institute of Animal Science, Guangdong Academy of Agricultural Sciences, Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South China, State Key Laboratory of Livestock and Poultry Breeding, Guangzhou, 510641, China.
J Mater Chem B. 2021 Nov 24;9(45):9383-9394. doi: 10.1039/d1tb01791h.
Biogenic amines (BAs) are important biomarkers to monitor meat spoilage. However, the design of efficient BA fluorescent probes with distinct colorimetric and ratiometric fluorescent dual-channels is still a critical challenge because of similar chemical properties and basicity between BAs and other amines. Herein, pyrrolopyrrole cyanine (PPCy-1) is reported to display distinctly high reactivity toward BAs through an ultrasensitive irreversible chromophore reaction for the first time. The reaction mechanism is ascribed to synergistic aza-Michael addition and B-N detachment, followed by hydrolysis to produce low-conjugated diketopyrrolopyrrole and heteroaromatic acetonitrile compounds. As a result, colorimetric and ratiometric fluorescent dual-channel (Δ = 188 nm and Δ = 151 nm) signals and a limit of detection up to 62.1 nM level for BA solution are acquired. In addition, the colorimetric detection of volatile amine vapor using the PPCy-1-loaded filter paper, showing a color change from green to yellow, is feasible. A simple and cost-effective fluorescence "turn on" method using the filter paper or the CAD-40 resin loaded with PPCy-1 to detect TVB (total volatile bases) originating from shrimp spoilage is further demonstrated.
生物胺（BAs）是监测肉类腐败的重要生物标志物。然而，由于 BA 与其他胺类具有相似的化学性质和碱性，因此设计具有明显比色和比率荧光双通道的高效 BA 荧光探针仍然是一个关键挑战。本文首次报道了吡咯并吡咯氰（PPCy-1）通过超灵敏不可逆生色反应对 BA 表现出明显的高反应性。反应机理归因于协同的氮杂迈克尔加成和 B-N 键断裂，随后水解生成低共轭二酮吡咯并吡咯和杂芳基乙腈化合物。结果，获得了比色和比率荧光双通道（Δ=188nm 和 Δ=151nm）信号和高达 62.1 nM 水平的 BA 溶液检测限。此外，使用负载 PPCy-1 的滤纸对挥发性胺蒸气的比色检测是可行的，显示出从绿色到黄色的颜色变化。进一步证明了使用滤纸或负载 PPCy-1 的 CAD-40 树脂的简单且具有成本效益的荧光“开启”方法来检测虾腐败产生的 TVB（总挥发性碱基）。
