Zhang Yuanlin, Zhang Kaiquan, Wang Jie, Tian Zhiyuan, Li Alexander D Q
School of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences (UCAS), Beijing 100049, P. R. China.
Nanoscale. 2015 Dec 14;7(46):19342-57. doi: 10.1039/c5nr05436b. Epub 2015 Oct 7.
Although fluorescence offers ultrasensitivity, real-world applications of fluorescence techniques encounter many practical problems. As a noninvasive means to investigate biomolecular mechanisms, pathways, and regulations in living cells, the intrinsic heterogeneity and inherent complexity of biological samples always generates optical interferences such as autofluorescence. Therefore, innovative fluorescence technologies are needed to enhance measurement reliability while not compromising sensitivity. In this review, we present current strategies that use photoswitchable nanoparticles to address these real-world challenges. The unique feature in these photoswitchable nanoparticles is that fundamental molecular photoswitches are playing the critical role of fluorescence modulation rather than traditional methods like modulating the light source. As a result, new innovative technologies that have recently emerged include super-resolution imaging, frequency-domain imaging, antiphase dual-color correlation, etc. Some of these methods improve imaging resolution down to the nanometer level, while others boost the detection sensitivity by orders of magnitude and confirm the nanoparticle probes unambiguously. These enhancements, which are not possible with non-photoswitching molecular probes, are the central topics of this review.
尽管荧光具有超高灵敏度，但荧光技术在实际应用中仍面临许多实际问题。作为一种研究活细胞中生物分子机制、途径和调控的非侵入性手段，生物样品固有的异质性和内在复杂性总是会产生诸如自发荧光等光学干扰。因此，需要创新的荧光技术来提高测量可靠性，同时又不影响灵敏度。在本综述中，我们介绍了当前利用可光开关纳米颗粒来应对这些实际挑战的策略。这些可光开关纳米颗粒的独特之处在于，基本的分子光开关在荧光调制中起着关键作用，而不是像调制光源这样的传统方法。结果，最近出现的新创新技术包括超分辨率成像、频域成像、反相双色关联等。其中一些方法将成像分辨率提高到纳米级别，而其他方法则将检测灵敏度提高几个数量级，并明确确认纳米颗粒探针。这些非光开关分子探针无法实现的增强是本综述的核心主题。
