Key Laboratory of Luminescent and Real-Time Analytical System (Southwest University), Chongqing Science and Technology Bureau, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
Chongqing Key Laboratory of Biomedical Analysis, Chongqing Science & Technology Commission, College of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
Talanta. 2020 Nov 1;219:121276. doi: 10.1016/j.talanta.2020.121276. Epub 2020 Jun 12.
The accurate and sensitive detection of biomarkers has great clinical value for the early diagnosis and treatment of cancer. Due to the excellent optical properties of carbon dots (CDs), CDs-based fluorescent detection methods have attracted increasing attention in bioanalytics. Signal reporters using CDs labeled hairpin DNA, based on Föster resonance energy transfer (FRET), have shown promise for the sensitive detection of biomarkers. In this work, a new method for sensitive biomarker detection using an enzyme-free amplified fluorescence strategy was developed. The strategy was based on FRET between CDs and graphene oxide (GO) combined with catalytic hairpin assembly (CHA). In the absence of the target, the CD-labeled hairpin DNA adsorb onto GO via hydrophobic and π-π stacking interactions, resulting in a FRET quenching of the CDs fluorescence. The introduction of the target could trigger the CHA circuits to form Y-shaped double-stranded DNA (dsDNA), resulting in a recovery of the CD's fluorescence signal. This novel strategy was successfully applied for the selective detection of prostate specific antigen (PSA) with a limit of detection (LOD) of 0.22 ng mL (3σ/k). Additionally, the method could be used to detect carcinoembryonic antigen (CEA) and adenosine triphosphate (ATP) with LOD of 0.56 ng mL (3σ/k) and 80 nM (3σ/k), respectively. Therefore, this work demonstrates a promising way to construct a sensitive and versatile detection platform.
准确而灵敏地检测生物标志物对于癌症的早期诊断和治疗具有重要的临床价值。由于碳点 (CDs) 具有优异的光学性能，基于 CDs 的荧光检测方法在生物分析中受到了越来越多的关注。使用标记有发夹 DNA 的 CDs 的信号报告器，基于Förster 共振能量转移 (FRET)，已显示出用于灵敏检测生物标志物的潜力。在这项工作中，开发了一种使用无酶扩增荧光策略进行灵敏生物标志物检测的新方法。该策略基于 CDs 与氧化石墨烯 (GO) 之间的 FRET 结合催化发夹组装 (CHA)。在不存在靶标的情况下，CD 标记的发夹 DNA 通过疏水和π-π 堆积相互作用吸附在 GO 上，导致 CDs 荧光的 FRET 猝灭。靶标的引入可以触发 CHA 电路形成 Y 型双链 DNA (dsDNA)，从而恢复 CD 的荧光信号。该新策略成功应用于前列腺特异性抗原 (PSA) 的选择性检测，检测限 (LOD) 为 0.22 ng mL（3σ/k）。此外，该方法还可用于检测癌胚抗原 (CEA) 和三磷酸腺苷 (ATP)，检测限分别为 0.56 ng mL（3σ/k）和 80 nM（3σ/k）。因此，这项工作证明了构建灵敏且多功能检测平台的一种很有前途的方法。
