College of Chemistry and Pharmaceutical Sciences and ‡Key Laboratory of Applied Mycology of Shandong Province, Qingdao Agricultural University , Qingdao 266109, China.
ACS Appl Mater Interfaces. 2018 Feb 7;10(5):4561-4568. doi: 10.1021/acsami.7b18676. Epub 2018 Jan 25.
Fluorescence biosensing strategy has drawn substantial attention due to their advantages of simplicity, convenience, sensitivity, and selectivity, but unsatisfactory structure stability, low fluorescence quantum yield, high cost of labeling, and strict reaction conditions associated with current fluorescence methods severely prohibit their potential application. To address these challenges, we herein propose an ultrasensitive label-free fluorescence biosensor by integrating hemin/G-quadruplex-catalyzed oxidation reaction with aggregation induced emission (AIE) fluorogen-based system. l-Cysteine/TPE-M, which is carefully and elaborately designed and developed, obviously contributes to strong fluorescence emission. In the presence of G-rich DNA along with K and hemin, efficient destruction of l-cysteine occurs due to hemin/G-quadruplex-catalyzed oxidation reactions. As a result, highly sensitive fluorescence detection of G-rich DNA is readily realized, with a detection limit down to 33 pM. As a validation for the further development of the proposed strategy, we also successfully construct ultrasensitive platforms for microRNA by incorporating the l-cysteine/TPE-M system with target-triggered cyclic amplification reaction. Thus, this proposed strategy is anticipated to find use in basic biochemical research and clinical diagnosis.
荧光生物传感策略因其简单、方便、灵敏和选择性而受到广泛关注，但目前的荧光方法存在结构稳定性差、荧光量子产率低、标记成本高以及严格的反应条件等问题，严重限制了其潜在应用。为了解决这些挑战，我们提出了一种超灵敏的无标记荧光生物传感器，该传感器将血红素/G-四链体催化氧化反应与基于聚集诱导发射（AIE）荧光团的系统相结合。精心设计和开发的 l-半胱氨酸/TPE-M 明显有助于产生强荧光发射。在富含 G 的 DNA 以及 K 和血红素存在的情况下，由于血红素/G-四链体催化氧化反应，l-半胱氨酸的有效破坏得以实现。因此，可实现对富含 G 的 DNA 的高灵敏度荧光检测，检测限低至 33 pM。作为对所提出策略进一步发展的验证，我们还通过将 l-半胱氨酸/TPE-M 系统与目标触发循环扩增反应相结合，成功构建了用于 microRNA 的超灵敏平台。因此，该策略有望在基础生物化学研究和临床诊断中得到应用。
