Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Key Laboratory of Luminescence Analysis and Molecular Sensing, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
Anal Chim Acta. 2022 Oct 16;1230:340393. doi: 10.1016/j.aca.2022.340393. Epub 2022 Sep 14.
The concentration variation of phenylalanine (Phe), an essential amino acid in humans, can cause metabolism disorders and even mental disability. Sensitive and convenient monitoring of Phe is therefore important for disease diagnosis. We describe here the establishment of a new aptamer-based, sensitive and label-free colorimetric Phe detection strategy by integrating catalytic hairpin assembly (CHA) and Mg-dependent DNAzyme amplification cascades. The target Phe coordinates with pentamethylcyclopentadienyl rhodium(III) chloride dimer [(Cp*RhCl)] to form a complex that has a high affinity to the corresponding aptamer sequence. Upon its binding to the aptamers in DNA duplex probes, ssDNA strands are released to trigger subsequent CHA reactions for the formation of many DNAzymes, which cleave the substrate signal probes to liberate lots of CHA initiation strands and free G-quadruplexes to realize the cascaded amplifications. Hemin further associates with the many G-quadruplexes to yield hemin/G-quadruplex mimicking peroxidases, which catalyze solution of substrate to exhibit highly enhanced UV-vis adsorption for detecting Phe at 0.19 μM level. At the meantime, the monitoring of Phe in diluted serums with high selectivity has also been demonstrated by the developed method, indicating its potential for simple diagnosis of Phe-related diseases.
苯丙氨酸（Phe）是人体必需的氨基酸，其浓度变化可导致代谢紊乱，甚至精神残疾。因此，灵敏、方便地监测 Phe 对疾病诊断非常重要。本文介绍了一种新的基于适体的、灵敏且无标记的比色 Phe 检测策略，该策略整合了催化发夹组装（CHA）和 Mg 依赖性 DNA 酶扩增级联反应。目标 Phe 与五甲基环戊二烯基铑(III)二聚体[(Cp*RhCl)]配位形成复合物，与相应的适体序列具有高亲和力。与 DNA 双链探针中的适体结合后，ssDNA 链被释放，引发随后的 CHA 反应，形成许多 DNA 酶，这些酶可切割底物信号探针，释放大量 CHA 起始链和游离 G-四链体，实现级联放大。随后，大量 G-四链体与血红素结合，产生血红素/G-四链体模拟过氧化物酶，可催化底物溶液显色，从而在 0.19 μM 水平下对 Phe 进行高灵敏检测。同时，该方法还对稀释血清中的 Phe 进行了高选择性监测，表明其在 Phe 相关疾病的简单诊断中具有应用潜力。
