研究发现,基质金属蛋白酶-9(MMP-9)在癌细胞侵袭中起着重要作用,转移,和肿瘤生长。但是,由于MMP蛋白家族的相似结构和功能,对MMP-9进行高度敏感和选择性的检测和靶向是一个挑战。在这里,基于适体诱导的SERS“热点”形成,开发了一种新型的表面增强拉曼散射(SERS)传感策略,用于极其灵敏和选择性地测定MMP-9。为了开发纳米传感器,用MMP-9适体及其互补链DNA1修饰一组金纳米球,而DNA2(与DNA1互补)和探针分子5,5'-二硫代双(2-硝基苯甲酸)(DTNB)接枝在另一组金纳米球的表面。在没有MMP-9的情况下,位于13nm金纳米球上的DTNB仅产生非常弱的SERS信号。然而,当MMP-9存在时,适体优先结合MMP-9以构建MMP-9适体复合物。裸DNA1可以识别并绑定到DNA2,这导致它们紧密靠近并创建SERS热点效果。由于这一行动,位于纳米粒子间隙的DTNB的SERS信号大大增强,实现对MMP-9的高灵敏度检测。由于热点效应是由特异性识别MMP-9的适体引起的,因此该方法对MMP-9检测表现出优异的选择性。基于高灵敏度和优异的选择性的好处,该方法用于区分正常细胞和癌细胞之间MMP-9水平的差异以及不同转移程度的癌细胞中MMP-9的表达。此外,该策略能准确反映细胞内MMP-9水平的动态变化,由MMP-9激活剂和抑制剂刺激。该策略有望转化为诊断与MMP-9相关的特定癌症并评估癌症发生程度的新技术。发展和转移。
Studies have found that matrix metalloproteinase-9 (MMP-9) plays a significant role in cancer cell invasion, metastasis, and tumor growth. But it is a challenge to go for highly sensitive and selective detection and targeting of MMP-9 due to the similar structure and function of the MMP proteins family. Herein, a novel surface-enhanced Raman scattering (SERS) sensing strategy was developed based on the aptamer-induced SERS \"hot spot\" formation for the extremely sensitive and selective determination of MMP-9. To develop the nanosensor, one group of gold nanospheres was modified with MMP-9 aptamer and its complementary strand DNA1, while DNA2 (complementary to DNA1) and the probe molecule 5,5\'-dithiobis-(2-nitrobenzoic acid) (DTNB) were grafted on the surface of the other group of gold nanospheres. In the absence of MMP-9, DTNB located on the 13-nm gold nanospheres has only generated a very weak SERS signal. However, when MMP-9 is present, the aptamer preferentially binds to the MMP-9 to construct MMP-9-aptamer complex. The bare DNA1 can recognize and bind to DNA2, which causes them to move in close proximity and create a SERS hot spot effect. Due to this action, the SERS signal of DTNB located at the nanoparticle gap is greatly enhanced, achieving highly sensitive detection of MMP-9. Since the hot spot effect is caused by the aptamer that specifically recognizes MMP-9, the approach exhibits excellent selectivity for MMP-9 detection. Based on the benefits of both high sensitivity and excellent selectivity, this method was used to distinguish the difference in MMP-9 levels between normal and cancer cells as well as the expression of MMP-9 from cancer cells with different degrees of metastasis. In addition, this strategy can accurately reflect the dynamic changes in intracellular MMP-9 levels, stimulated by the MMP-9 activator and inhibitor. This strategy is expected to be transformed into a new technique for diagnosis of specific cancers related to MMP-9 and assessing the extent of cancer occurrence, development and metastasis.