Adulterated Fish Recognition Employing SnO2 Nanostructure-Based Chemiresistive Sensor

The letter reports a flowerlike SnO
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nanostructure-based chemiresistive type formaldehyde sensor to detect formalin adulteration in fish. A low-temperature hydrothermal technique was adopted to prepare the sensing material. The structural and morphological characterizations of the synthesized material were performed using X-ray diffraction (XRD) and a field emission scanning electron microscope (FESEM), respectively. Using a micropipette, the sensing material was drop casted over interdigitated electrodes built on an alumina substrate to fabricate the sensor device. The gas sensing study showed that the sensor was notably sensitive toward formaldehyde. The theoretical limit of detection of the sensor was found to be 870 ppb. The sensing behavior was studied toward the fish emitted vapors, where the sensor offered significant distinction among the fresh and adulterated fish samples.