Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Graz, Austria.
Anal Chim Acta. 2013 Jul 17;787:219-25. doi: 10.1016/j.aca.2013.05.032. Epub 2013 May 27.
A new approach for referencing of colorimetric chemosensors is described. The sensing materials rely on combination of absorption-based indicators and inorganic phosphors. Chromium(III)-activated yttrium aluminum borate and gadolinium aluminum borate were chosen to illustrate the new sensing scheme due to their spectral properties and high chemical and photochemical stability. The ratiometric luminescence read-out becomes possible due to the overlap of at least one form of the indicator with broadband emission (650-900 nm) or excitation (400-700 nm) of the phosphor. Long luminescence decay time of the phosphors (80-150 μs) allows for complete elimination of background fluorescence originating from the media, optical components or the indicator. The versatile scheme enables robust read-out of numerous colorimetric chemosensors and probes. Examples of sensing pH (using a BF2-chelated tetraarylazadipyrromethene dye as an indicator) and carbon dioxide (a triphenylmethane dye as an indicator) are provided. It is also demonstrated that temperature can be accessed via luminescence decay time of the phosphor to enable compensation of the sensors for temperature effects.
描述了一种新的比色化学传感器的参比方法。传感材料依赖于基于吸收的指示剂和无机荧光粉的组合。由于其光谱特性和高化学和光化学稳定性，选择了铬(III)激活的钇铝硼酸盐和钆铝硼酸盐来说明新的传感方案。由于指示剂的至少一种形式与荧光粉的宽带发射（650-900nm）或激发（400-700nm）重叠，因此可以实现比率荧光读出。荧光粉的长荧光衰减时间（80-150μs）允许完全消除来自介质、光学元件或指示剂的背景荧光。这种多功能方案能够稳健地读取众多比色化学传感器和探针。提供了用于感测 pH（使用 BF2 螯合的四芳基偶氮二吡咯甲川染料作为指示剂）和二氧化碳（作为指示剂的三苯基甲烷染料）的示例。还证明可以通过荧光粉的荧光衰减时间来访问温度，从而能够为温度效应补偿传感器。
