Department of Chemistry, Fudan University, Shanghai 200438, P. R. China.
Analyst. 2018 Oct 22;143(21):5120-5126. doi: 10.1039/c8an00967h.
Luminescence-quenching based optical oxygen sensors have wide applications in many fields, which have already replaced almost 40% of the commercial market share dominated previously by the Clark oxygen electrode. The majority of optical oxygen sensors are based on lifetime measurement, which are precise, but are relatively expensive, and require high-speed electronics and detecting circuits. Alternatively, oxygen concentration can be measured via a luminescence intensity change, which is a referenced approach according to the Stern-Volmer equation. However, luminescence intensity based measurement tends to be highly influenced by background light. At a given sensor composition, different instrumentation setups, sensor surface roughnesses and thicknesses, and environmental light will result in significantly different calibration curves and sensitivities. This makes luminescence-intensity based optical sensors almost impossible to use practically, because each sensor needs to be recalibrated before use, and the calibration curve each time is quite different. We have solved this problem by introducing a new background-subtraction strategy. After background subtraction, oxygen sensors with different probe concentrations, instrumentation setups, surface roughnesses, supporting matrixes, and at different temperatures present identical calibration curves. This could greatly reduce the calibration task during practical use. Combined with the advantages of low price and a simple optical configuration, the new method will significantly promote wider applications of optical oxygen sensors.
基于荧光猝灭的光学氧传感器在许多领域有广泛的应用，已经取代了之前由克拉克氧电极主导的近 40%的商业市场份额。大多数光学氧传感器基于寿命测量，这种方法虽然精确，但相对昂贵，需要高速电子和检测电路。或者，可以通过荧光强度变化来测量氧浓度，这是根据斯特恩-沃尔默方程的参考方法。然而，基于荧光强度的测量容易受到背景光的强烈影响。在给定的传感器组成、不同的仪器设置、传感器表面粗糙度和厚度以及环境光下，会导致显著不同的校准曲线和灵敏度。这使得基于荧光强度的光学传感器几乎不可能实际应用，因为每个传感器在使用前都需要重新校准，而且每次的校准曲线都非常不同。我们通过引入一种新的背景减除策略解决了这个问题。经过背景减除后，具有不同探针浓度、仪器设置、表面粗糙度、支撑基质和不同温度的氧传感器呈现出相同的校准曲线。这可以大大减少实际使用中的校准任务。结合价格低廉和光学结构简单的优点，这种新方法将显著促进光学氧传感器的更广泛应用。
