Low-Power Detection of Food Preservatives by a Novel Nanowire-Based Sensor Array

Abstract

Food preservatives are compounds that are used for the treatment of food to improve the shelf life. In the food industry, it is necessary to monitor all processes for both safety and quality of the product. An electronic nose (or e-nose) is a biomimetic olfactory system that could find numerous industrial applications, including food quality control. Commercial electronic noses are based on sensor arrays composed by a combination of different sensors, which include conductometric metal oxide devices. Metal oxide nanowires are considered among the most promising materials for the fabrication of novel sensing devices, which can enhance the overall performances of e-noses in food applications. The present work reports the fabrication of a novel sensor array based on SnO2, CuO, and WO3 nanowires deposited on top of μHPs provided by ams Sensor Solutions Germany GmbH. The array was tested for the discrimination of four typical compounds added to food products or used for their treatment to increase the shelf life: ethanol, acetone, nitrogen dioxide, and ozone. Results are very promising; the sensors array was able to operate for a long time, consuming less than 50 mW for each single sensor, and principal component analysis (PCA) confirmed that the device was able to discriminate between different compounds.

Chemical Gas Sensors Studied at SENSOR Lab, Brescia (Italy): From Conventional to Energy-Efficient and Biocompatible Composite Structures

“…According to the specifications of these micro-hotplate substrates, they can work up to 450 • C for long-term operation. However, the substrates were stressed at much higher temperatures (≤870 • C) during the synthesis of the metal oxide nanostructures and sustained without any critical breakdown [23]. The operating temperature variation of this E1 20:20 substrate depending on the applied power ( Figure 1d) is similar to that of micro-hotplate manufactured by SAMLAB.…”

A Review on the Use of Impedimetric Sensors for the Inspection of Food Quality

“…Zappa et al showed that [ 120 ] certain types of nanomaterials, such as tungsten, copper and tin, were being used to form oxide-based nanowires for the detection of food preservatives. These nanowires were subsequently used to form sensor arrays for low-power detection processes.…”

“…Each of the sensors in the developed arrays consumed power less than 50 mW and operate on the principle component analysis (PCA) technique. Figure 3 a [ 120 ] shows the schematic diagram of the mounting of the nanowires on the hotplates to form the chemical sensors. The hotplates were initially diced and deposited with a metallic layer using the magnetron sputtering technique.…”

“…Finally, pads were connected to the pins using gold wires via the electro-soldering technique. Figure 3 b–d [ 120 ] shows the optical images of the nanowires. It is seen that the thermal oxidation process assisted in the patterning of the nanowires, with the help of simple shadow masking.…”

The Self-Calibration Method for the Vertex Distance of the Elliptical Paraboloid Array

“…Wu et al [11] presented a novel instrumentation system, including an infrared laser source and a photodiode sensor array, to provide an accurate measurement of the gas void fraction of two-phase CO 2 flow. Dario [12] demonstrated a novel sensor array based on SnO 2 , CuO, and WO 2 nanowires, which is able to discriminate four typical compounds added to food products. Atte et al [13] demonstrated that the bioimpedance sensor array has the ability to achieve long-term monitoring of intact skin and acute wound healing from beneath primary dressings.…”