College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, China.
Nanoscale. 2018 Jun 14;10(23):11134-11142. doi: 10.1039/c8nr02780c.
Fluorescent copper nanoparticles (CuNPs) have received great attention due to their distinct characteristics of facile synthesis, tunable fluorescence emission, high photostability, and biological compatibility, and they have been widely used for chemical and biological analyses. Bleomycins (BLMs) are widely used antitumor agents for the clinical treatment of various cancers. Here, we develop a sensitive and label-free fluorescence method for the quantitative detection of BLM on the basis of BLM-initiated enzymatic polymerization-mediated synthesis of fluorescent CuNPs. We design two hairpin DNAs: one (Hp1) for the recognition of BLM and the other (Hp2) for signal amplification. In the presence of BLM, it may recognize and cleave the 5'-GC-3' site of the Hp1 stem, releasing the 8-17 DNAzyme fragment. The resultant 8-17 DNAzyme fragments may bind with the loop of Hp2 to form a partial double-stranded DNA (dsDNA) duplex, initiating the cyclic cleavage of Hp2 in the presence of Zn2+-dependent DNAzymes and generating numerous new DNA fragments with the free 3'-OH terminal, which can induce the formation of a poly(thymine) (poly-T) sequence with the assistance of terminal deoxynucleotidyl transferase (TdTase). Subsequently, the ploy-T sequence may function as the template for the synthesis of CuNPs with strong fluorescence emission. This method shows good selectivity and high sensitivity with a detection limit as low as 8.1 × 10-16 M, and it exhibits good performance in serum samples. Moreover, this method has distinct advantages of simplicity and low cost, holding great potential in clinical diagnosis and biomedical research.
荧光铜纳米粒子（CuNPs）由于其易于合成、可调谐荧光发射、高光稳定性和生物相容性等独特特性而备受关注，已被广泛应用于化学和生物分析。博来霉素（BLMs）是广泛用于临床治疗各种癌症的抗肿瘤药物。在这里，我们基于 BLM 引发的酶聚合介导的荧光 CuNPs 合成，开发了一种用于 BLM 定量检测的灵敏且无标记的荧光方法。我们设计了两条发夹 DNA：一条（Hp1）用于识别 BLM，另一条（Hp2）用于信号放大。在 BLM 的存在下，它可能识别并切割 Hp1 茎的 5'-GC-3'位点，释放 8-17 DNA 酶片段。所得的 8-17 DNA 酶片段可能与 Hp2 的环结合，形成部分双链 DNA（dsDNA）双链，在 Zn2+-依赖性 DNA 酶的存在下引发 Hp2 的循环切割，并产生许多具有游离 3'-OH 末端的新 DNA 片段，在末端脱氧核苷酸转移酶（TdTase）的协助下，可以诱导形成具有强荧光发射的聚（胸腺嘧啶）（poly-T）序列。该方法具有良好的选择性和高灵敏度，检测限低至 8.1×10-16 M，在血清样本中表现出良好的性能。此外，该方法具有简单、成本低的显著优势，在临床诊断和生物医学研究中具有很大的应用潜力。
