Design And Implement Of An Indoor Formaldehyde Electrochemical Sensor Based On Silicon Nano Structure Electrode

Substance with high level of toxicity, formaldehyde is often used for upholstery materials like wood-based composite and bonding compound. Living long-term in an environment with low concentration of formaldehyde will cause serious hazard to human health. In the current formaldehyde test methods, electrochemical detection is considered as the mainstream method because of its high sensitivity and good stability. And with its advantages as small volume, high performance and easy integration, electrochemical sensor with silicon micro-nanostructure has become a hot research direction of formaldehyde electrochemical sensors.Based on silicon nanowires(SiNWs) and electroless plating nickle-palladium electrode, this paper designs an indoor formaldehyde electrochemical sensor, studies electrochemical properties of this sensor by electrochemical workstation and finally builds the indoor formaldehyde monitoring experimental device based on ARM platform. Research works of this paper are related to the following sections:First, this paper analyzes and compares domestic and foreign formaldehyde test methods.on this basis, a development program of formaldehyde electrochemical sensor is proposed.Second, according to working principle of formaldehyde electrochemical sensor, we design the architecture of this sensor; by analyzing cyclic voltammetry and chronoamperometry of silicon nanostructure electrode, we prepare formaldehyde electrochemical sensor. According to analysis, we find that a linear relationship exists between the formaldehyde concentration and the peak current value produced by the sensor and that this sensor has a good stability and an anti-jamming character when the range of formaldehyde concentration is 0 mmol L-1 – 21.0 mmol L-1.According to electrochemical properties of formaldehyde electrochemical sensor, we build the detecting device of formaldehyde examination. This detecting device based on ARM9 board is able to achieve the acquisition and display of formaldehyde concentration, through the porting of embedded Linux operating system and by combining with the corresponding peripheral hardware modules.With the function to acquire, to converse the sensor signals and to display the information, the hardware of this system is composed of ARM9 core module, power electronic module, waveform generator module and signal regulated module. With the function to process the system signals and to control the hardware, the system software is composed of embedded development platform, driver and control procedures of corresponding modules. It is able to acquire and converse formaldehyde concentration signals and to display the CV curve by using the human-computer interface built with Qt plugin.Finally, we conduct system debugging and deviation analysis. The experiments show that experimental devices we design for the formaldehyde electrochemical sensor have advantages of low cost, excellent detection performance and facility to use, which meets our expected design requirements.