Lau King Tong, Baldwin Susan, Shepherd Roderick L, Dietz Paul H, Yerzunis William S, Diamond Dermot
School of Chemical Sciences, National Centre for Sensor Research, Dublin City University, Dublin, Ireland.
Talanta. 2004 May 10;63(1):167-73. doi: 10.1016/j.talanta.2003.10.034.
The development of a novel, low power optical sensing platform based on light emitting diodes (LEDs) is described. The sensor is constructed from a pair of LEDs fused together at an angle where one LED functions as the light source and the other LED is reverse biased to function as a light detector. Sensor function is based on the level of light received by the detector diode, which varies with the reflectance of the interface between the device and its environment, or the chemochromic membrane that covers the device. A simple microprocessor circuit is used to measure the time taken for the photon-induced current to discharge the detector LED from an initial 5V (logic 1) to 1.7V (logic zero). This sensing device has been successfully used for colour and colour-based pH measurements and offers extremely high sensitivity, enabling detection down to the sub micro molar level of dyes.
本文描述了一种基于发光二极管（LED）的新型低功耗光学传感平台的开发。该传感器由一对以一定角度融合在一起的LED构成，其中一个LED用作光源，另一个LED反向偏置用作光探测器。传感器功能基于探测器二极管接收到的光的强度，该强度会随着器件与其环境之间界面的反射率或覆盖器件的化学变色膜而变化。一个简单的微处理器电路用于测量光子感应电流将探测器LED从初始的5V（逻辑1）放电到1.7V（逻辑0）所需的时间。这种传感装置已成功用于颜色和基于颜色的pH测量，并具有极高的灵敏度，能够检测低至亚微摩尔水平的染料。
