Integrating Electrochemical and Colorimetric Sensors with a Webcam Readout for Multiple Gas Detection

Abstract

Multisensor detectors have merits of low cost, compact size, and capability of supplying accurate and reliable information otherwise hard to obtain by any single sensors. They are therefore highly desired in various applications. Despite the advantages and needs, they face great challenges in technique especially when integrating sensors with different sensing principles. To bridge the gap between the demand and technique, we here demonstrated an integration of electrochemical and colorimetric sensors with a webcam readout for multiple gas detection. Designed with two parallel gas channels but independent sensor cells, the dual-sensor detector could simultaneously detect each gas from their gas mixture by analysis of the group photo of the two sensors. Using Ag electro-dissolution as reporter, the bipolar electrochemical sensor achieved quantitative analysis for the first time thanks to application of pulse voltage. The sacrificed Ag layer used in the bipolar electrochemical (EC) sensor was recycled from CD, which further decreased the sensor cost and supplied a new way of CD recycling. The EC O2 sensor response, edge displacement of Ag layer due to electrochemical dissolution, has a linear relationship with O2 concentration ranging from 0 to 30% and has good selectivity to common oxidative gases. The colorimetric NO2 sensor linearly responded to NO2 concentrations ranging from 0 to 230 ppb with low detection limit of 10 ppb, good selectivity, and humidity tolerance. This integration method could be extended to integrating other gas sensors.

Nitrogen Dioxide Optical Sensor Based on Redox-Active Tetrazolium/Pluronic Nanoparticles Embedded in PDMS Membranes

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Ultrasensitive Electrochemiluminescence Biosensor Based on Closed Bipolar Electrode for Alkaline Phosphatase Detection in Single Liver Cancer Cell

“…In the past two decades, bipolar electrodes (BPEs) have emerged in the field of analysis due to easy control, no direct electrical contact, easy miniaturization, and portability and have attracted the attention of many scientific researchers. − A common strategy used to study bipolar electrodes is to combine electrochemiluminescence (ECL) based on their outstanding advantages of high detection sensitivity, no need for excitation light source, and simple instrumentation . The ECL technology is a combination of chemiluminescence and electrochemistry, which not only has the sensitivity and wide dynamic range of chemiluminescence but also holds the simplicity and facility of electrochemical detection. , The ideal combination of closed bipolar electrodes and electrochemiluminescence technology has resulted in rapid development for application in biological analysis .…”