Extending the Longevity of Fluorescence-Based\nSensor Arrays Using Adaptive Exposure

Abstract

Fluorescent microbead sensor arrays were prepared to\ndetermine sensor array longevity. Sensor longevity is\nlimited by photobleaching of the dyes attached to the\nmicrobeads and presents one of the biggest drawbacks\nof most fluorescent dye-based arrays. Responses of an\narray of organic vapor sensors were acquired for 2 weeks\nto evaluate the sensor performance over time. Photobleaching effects were overcome in two ways: (1) by\nlimiting the excitation light power and gradually increasing\nthe power at a rate comparable to the sensor photobleaching rates and (2) by illuminating subsections of the array\nthrough an optical slit. Both approaches extended the\nlongevity of a sensor array. During the longevity study,\nthe sensor arrays were employed to test their ability to\ncorrectly distinguish between responses to seven vapors.\nA high classification accuracy (99.8%) was obtained after\n17 700 exposures for vapor responses collected over two\nweeks using only ∼8% of the array's surface area.