School of Chemistry, the Raymond and Beverly Sackler Faculty of Exact Sciences and ‡The Center for Nanoscience and Nanotechnology, Tel-Aviv University , Tel Aviv 69978, Israel.
Nano Lett. 2013 Jul 10;13(7):3157-68. doi: 10.1021/nl401169k. Epub 2013 Jun 17.
Quantitative detection of biological and chemical species is critical to numerous areas of medical and life sciences. In this context, information regarding pH is of central importance in multiple areas, from chemical analysis, through biomedical basic studies and medicine, to industry. Therefore, a continuous interest exists in developing new, rapid, miniature, biocompatible and highly sensitive pH sensors for minute fluid volumes. Here, we present a new paradigm in the development of optoelectrical sensing nanodevices with built-in self-calibrating capabilities. The proposed electrical devices, modified with a photoactive switchable molecular recognition layer, can be optically switched between two chemically different states, each having different chemical binding constants and as a consequence affecting the device surface potential at different extents, thus allowing the ratiometric internal calibration of the sensing event. At each point in time, the ratio of the electrical signals measured in the ground and excited states, respectively, allows for the absolute concentration measurement of the molecular species under interest, without the need for electrical calibration of individual devices. Furthermore, we applied these devices for the real-time monitoring of cellular metabolic activity, extra- and intracellularly, as a potential future tool for the performance of basic cell biology studies and high-throughput personalized medicine-oriented research, involving single cells and tissues. This new concept can be readily expanded to the sensing of additional chemical and biological species by the use of additional photoactive switchable receptors. Moreover, this newly demonstrated coupling between surface-confined photoactive molecular species and nanosensing devices could be utilized in the near future in the development of devices of higher complexity for both the simultaneous control and monitoring of chemical and biological processes with nanoscale resolution control.
定量检测生物和化学物质对医学和生命科学的众多领域至关重要。在这种情况下，pH 值的信息在从化学分析到生物医学基础研究和医学再到工业的多个领域都具有核心重要性。因此，人们一直致力于开发新的、快速的、微型的、生物兼容的和高灵敏度的 pH 传感器，用于检测微小的流体体积。在这里，我们提出了一种新的光电传感纳米器件的发展范例，该器件具有内置自校准功能。所提出的电设备经过光活性可切换分子识别层的修饰，可以在两种化学上不同的状态之间进行光学切换，每种状态都具有不同的化学结合常数，因此会在不同程度上影响器件表面的电位，从而允许对传感事件进行比率内校准。在每个时间点，分别在基态和激发态下测量的电信号的比值允许对感兴趣的分子物种的绝对浓度进行测量，而无需对单个设备进行电校准。此外，我们将这些设备应用于细胞代谢活性的实时监测，包括细胞外和细胞内，作为未来用于基础细胞生物学研究和高通量面向个性化医学研究的潜在工具，涉及单细胞和组织。通过使用额外的光活性可切换受体，可以很容易地将这个新概念扩展到对其他化学和生物物质的传感。此外，表面受限的光活性分子物种与纳米传感设备之间新展示的这种偶联可以在不久的将来用于开发更复杂的设备，用于以纳米级分辨率控制同时控制和监测化学和生物过程。
