Key Laboratory of Luminescence Analysis and Molecular Sensing (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, PR China.
College of Food Science, Southwest University, Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Chongqing, 400715, PR China.
Biosens Bioelectron. 2023 Oct 15;238:115580. doi: 10.1016/j.bios.2023.115580. Epub 2023 Aug 9.
Herein, the methionine (Met)/N-acetyl-L-cysteine (NAC) templated copper nanoclusters (Met/NAC-Cu NCs) with tunable near-infrared region (NIR) electrochemiluminescence (ECL) emission wavelength was firstly synthesized as emitter for the ultrasensitive detection of matrix metalloproteinase-2 (MMP-2). Significantly, the NAC played the role of template and reductant of cupric to acquire Cu NCs, and the surface defect regulator Met was used to connect NAC through -S-S- bond, which could heighten the surface defect of Cu NCs to continuously regulate the maximum ECL emission by successively controlling the molar ratio of Met and NAC, leading to the ECL emission wavelength of Cu NCs ranged from 680 nm to 750 nm. In addition, a rapid target triggered catalyst hairpin assembly (CHA) recycling amplification strategy was constructed through orderly and equidistantly arranging hairpin to increase its local concentration, resulting in greatly accelerated signal amplification efficiency and reaction rate. As a proof of concept, based on Met/NAC-Cu NCs as NIR ECL emitter and effective signal amplification tactic, a super-sensitive ECL biosensor was fabricated to detect target MMP-2 with the detection limit (LOD) as low as 1.65 fg/mL and successfully utilized for detecting of MMP-2 that from Hela and MCF-7 cancer cells. This research provided a wonderful avenue for regulating the optical performance of metal nanoclusters-based ECL emitters, and the developed neoteric NIR ECL emitter with the merits of less photochemical damage and deeper tissue penetration exhibited great potential in ultrasensitive biosensing and high-definition ECL imaging.
在此，首次合成了甲硫氨酸（Met）/N-乙酰-L-半胱氨酸（NAC）模板铜纳米簇（Met/NAC-Cu NCs），其具有可调谐的近红外区（NIR）电化学发光（ECL）发射波长，可用作发射体来超灵敏检测基质金属蛋白酶-2（MMP-2）。值得注意的是，NAC 作为铜离子的模板和还原剂，获得了 Cu NCs，而表面缺陷调节剂 Met 则用于通过 -S-S-键连接 NAC，这可以提高 Cu NCs 的表面缺陷，通过连续控制 Met 和 NAC 的摩尔比，持续调节最大 ECL 发射，从而使 Cu NCs 的 ECL 发射波长从 680nm 到 750nm 不等。此外，通过有序且等距地排列发夹，构建了一种快速的目标触发催化剂发夹组装（CHA）循环放大策略，以增加其局部浓度，从而大大提高了信号放大效率和反应速率。作为概念验证，基于 Met/NAC-Cu NCs 作为近红外 ECL 发射器和有效的信号放大策略，构建了一种超灵敏的 ECL 生物传感器，用于检测目标 MMP-2，其检测限（LOD）低至 1.65fg/mL，并成功用于检测 Hela 和 MCF-7 癌细胞中的 MMP-2。该研究为调节基于金属纳米簇的 ECL 发射器的光学性能提供了一条很好的途径，所开发的新型近红外 ECL 发射器具有光化学损伤小和组织穿透深的优点，在超灵敏生物传感和高清晰度 ECL 成像方面具有巨大的应用潜力。
