Portable Colorimetrical Sensor Array-Based Vapor Detection System

Today, the importance of the qualitative and quantitative analysis of food gas industry, environmental monitoring, health care, pharmaceutical industry, aerospace, chemical control and police customs and many other industries is growing. The most promising gas analysis technology is the electronic nose technology. Electronic nose is an instrument, including selective electrochemical sensor array and an appropriate pattern recognition system, able to identify a single or complex odors.Based on this, here we demonstrate a sensor array using dye-based smartphones volatile organic lightweight portable gas detection system. Specific contents are as follows:Metal porphyrins, PH indicator and gaschromic dyes can react with gases and have color changes. By use of this characteristic, we drop these dyes in silica gel thin layer chromatography plates to prepare color-sensitive sensor array, and then encapsulates the array into the gas detection chamber made by PDMS. On an optical platform, we build an optical path monitoring color changes of dyed array, which provides the foundation for the later development of smart phones based detection platform.We designed a detection device based on smart phones, constructed miniature optical path with light guide transmission imaging, utilized the OTG or battery power supply, and designed to draw the structure of the matching accessories of mobile phone finally made by 3D printing. The above is the detection device hardware platform. Also, I accomplished the software platform. I programmed an Android smart-phone gas detection application, and the software can time, takes pictures, processes images and determines the measured gas species. On such hardware and software platform, using color-sensitive sensor array, methanol, ethanol, and chloroform and other organic vapors’saturated steam can be detected. Color sensitive array has good sensitivity and selectivity; as dye species increasing, the sensitivityand selectivity of the sensor array increases; the smart-phone based gas detection devices have strong practical value.Metal porphyrin dyes can react with gases and fluorescence intensity changes. Taking advantage of this characteristic, we drop dyes on thin layer chromatography silica plates to fabricate fluorescent gas sensor array. Designed smart-phone gas detection devices with fluorescence-based sensor array, modified the design of the matching accessories of mobile phone, built new light path and power supply module; modified Android application software. On the new gas detection platform, using a fluorescent sensor array, saturated steam of methanol, ethanol, acetone and n-hexane were tested. Fluorescence sensor array has better sensitivity and selectivity; the smart-phone based gas detection devices have strong practical value.