چكيده به لاتين
Sensors, also known as freshness indicators, play a crucial role in assessing the quality of fruits, considering factors like freshness, ripeness, and firmness. The inclusion of freshness indicators on fruit packages allows for control over the package's internal and external environments, enabling consumers to make informed decisions about the fruit's quality. The rapid detection of volatile organic biomarkers poses numerous challenges, including sensitivity, accuracy, and selectivity. This research addresses these challenges by introducing a highly effective colorimetric solid-state sensor array designed for monitoring the health of apples, bananas, and pears. This is achieved by tracking key markers such as acetaldehyde, propionaldehyde, and acetone. The sensors are crafted by incorporating stabilized organic dyes with zinc oxide nanoparticles into a hydrogel mixture of xanthan and Tragacanth gum, which is then affixed to a calcium alginate pad. Various operational variables, including response time, ratios of mixed organic dyes, the combination of xanthan and Tragacanth hydrogels, glycerol volume, zinc oxide nanoparticle solution volume, and sample concentration, were thoroughly investigated and optimized to attain optimal performance. For acetaldehyde, the limit of detection was determined as 0.11 ppm, with a limit of quantification of 0.36 ppm within the detection range of 0.117-3.92 ppm. The repeatability of the sensor, assessed through five measurements at an acetaldehyde biomarker concentration of 1.96 ppm, yielded a relative standard deviation of 6.7% under optimal conditions. Under optimal conditions, the limit of detection for propionaldehyde was 0.14 ppm, with a limit of quantification of 0.46 ppm within the detection range of 0.153-5.202 ppm. The repeatability test, conducted with five measurements at a propionaldehyde biomarker concentration of 1.53 ppm, resulted in a relative standard deviation of 10.69%. For acetone, the limit of detection was established at 0.07 ppm, with a limit of quantification of 0.23 ppm within the detection range of 0.088-5.032 ppm. The repeatability analysis, based on five measurements at an acetone biomarker concentration of 1.48 ppm, demonstrated a relative standard deviation of 7.98%. Utilizing a smartphone equipped with a color analysis application, the research successfully detected relative color changes. Practical applications of the sensors in real samples of bananas, apples, and pears at various temperatures were explored, marking a significant advancement in commercializing cost-effective, user-friendly, automatable, array-able, and non-toxic eye-readable colorimetric sensors.
