College of Materials and Chemical Engineering, Minjiang University, Fuzhou, Fujian, 350108, China.
The School of Pharmacy, Fujian Medical University, Fuzhou, Fujian, 350108, China.
Anal Chim Acta. 2024 Nov 1;1328:343161. doi: 10.1016/j.aca.2024.343161. Epub 2024 Aug 28.
Rapid industrial development has generated serious pollution, including the presence of toxic and harmful heavy metal ions. Among them, trivalent chromium ion (Cr) is a very important element that poses a threat to life and health in our industrial wastewater pollution. Thus, it is important to develop efficient fluorescence methods for Cr detection. In this study, an upconversion luminescence biosensor for detecting Cr was constructed based on a DNAzyme, strand displacement reaction (SDR), and DNA-functionalized upconversion nanoparticles (UCNPs).
The sulfonate-rich poly (sodium 4-styrene sulfonate) (PSS) was modified onto the surface of UCNPs, forming UCNPs@PSS. Then, NH-Capture probe DNA (NH-Cp) was further modified onto the UCNPs@PSS surface through sulfonylation, resulting in UCNPs@PSS@NH-Cp. The DNAzyme activated by Cr triggered the release of the primer probe (Pp), which initiated the SDR system cycle, thereby releasing a tetramethylrhodamine (TAMRA)-modified signal probe (TAMRA-Sp). Finally, UCNPs@PSS@NH-Cp bound to TAMRA-Sp through complementary base pairing, causing UCNPs and TAMRA to approach each other. Because of the luminescence resonance energy transfer (LRET) mechanism, the upconversion luminescence (UCL) signal of the UCNPs was quenched by TAMRA, enabling the detection of Cr by the change of I/I ratio. This biosensor has good stability, selectivity, and sensitivity, with a linear range of 0.5-75 nM and a detection limit of 0.135 nM for Cr.
Firstly, based on LRET between UCNPs and TAMRA, the quantitative analysis of Cr is achieved through the changes of ratio fluorescence. Secondly, the specificity of the biosensor is improved by utilizing the specific recognition of DNA enzymes. Thirdly, the signal amplification technology of the SDR cycle greatly improves the sensitivity of biosensor. This biosensor will be useful for future environmental safety monitoring and biopsy of biological fluids.
快速的工业发展产生了严重的污染，包括有毒有害重金属离子的存在。其中，三价铬离子（Cr）是一种非常重要的元素，对我们工业废水中的生命和健康构成威胁。因此，开发高效的荧光方法来检测 Cr 离子显得尤为重要。本研究构建了一种基于 DNA 酶、链置换反应（SDR）和 DNA 功能化上转换纳米粒子（UCNPs）的检测 Cr 的上转换发光生物传感器。
富磺酸基的聚（4-苯乙烯磺酸钠）（PSS）修饰在上转换纳米粒子（UCNPs）表面，形成 UCNPs@PSS。然后，通过磺化作用进一步将 NH 捕获探针 DNA（NH-Cp）修饰到 UCNPs@PSS 表面，得到 UCNPs@PSS@NH-Cp。Cr 激活的 DNA 酶触发引物探针（Pp）的释放，从而启动 SDR 系统循环，从而释放出四甲基罗丹明（TAMRA）修饰的信号探针（TAMRA-Sp）。最后，UCNPs@PSS@NH-Cp 通过互补碱基配对与 TAMRA-Sp 结合，使 UCNPs 和 TAMRA 彼此靠近。由于发光共振能量转移（LRET）机制，UCNPs 的上转换发光（UCL）信号被 TAMRA 猝灭，从而通过 I/I 比值的变化来检测 Cr。该生物传感器具有良好的稳定性、选择性和灵敏度，Cr 的线性范围为 0.5-75 nM，检测限为 0.135 nM。
首先，基于 UCNPs 和 TAMRA 之间的 LRET，通过荧光强度比的变化实现 Cr 的定量分析。其次，利用 DNA 酶的特异性识别提高了生物传感器的特异性。第三，SDR 循环的信号放大技术极大地提高了生物传感器的灵敏度。该生物传感器将有助于未来环境安全监测和生物体液的活检。
