A Biomass-Based Colorimetric Sulfur Dioxide Gas Sensor for Smart Packaging

Abstract

Sulfur dioxide (SO2) gas, which can effectively prohibit the growth of pathogenic microorganisms, has been internationally used in commercial food packaging to maintain high-quality food and reduce the incidence of foodborne illnesses. However, the current mainstream methods for SO2 detection are either large and expensive instruments or synthesized chemical-based labels, which are not suitable for large-scale gas detection in food packaging. Recently, we discovered that petunia dye (PD), which is extracted from natural petunia flowers, demonstrates a highly sensitive colorimetric response to SO2 gas with its total color difference (ΔE) modulation reaching up to 74.8 and detection limit down to 1.52 ppm. To apply the extracted petunia dye in smart packaging for real-time gas sensing and food-quality prediction, a flexible and freestanding PD-based SO2 detection label is prepared by incorporating PD in biopolymers and assembling the films through a layer-by-layer approach. The developed label is utilized to predict grapes’ quality and safety by monitoring the embedded SO2 gas concentration. The developed colorimetric SO2 detection label could potentially be used as an intelligent gas sensor for food status prediction in daily life, food storage, and supply chains.

The Challenges and Opportunities for TiO2 Nanostructures in Gas Sensing

“…Subsequently, when exposed to the analyte gas, the resistance of TiO 2 -based gas sensors will increase or decrease according to the type of analyte gas (oxidizing or reducing). For example, reducing gases such as H 2 S, formaldehyde, NH 3 , CO, and ethanol inject electrons into the conduction band (CB) of TiO 2 , leading to a decrease in TiO 2 resistance. , In contrast, oxidizing gases such as O 3 , NO x , and SO 2 induce resistance changes in the opposite direction. , …”

Taming Janus-Faced Quinoline-Derived Fluorescent Probes for Dual-Channel Distinguishable Visualization of HSO3– and HClO in Dried Foods and Living Cells

“…Freshness preservation of food samples can be effectively achieved in the presence of bisulfite salts . Whereas, artificial overloading of superfluous HSO 3 – may risk food safety.…”

“…Freshness preservation of food samples can be effectively achieved in the presence of bisulfite salts. 42 Whereas, artificial overloading of superfluous HSO 3 − may risk food safety. Thus, scrutinizing the content of HSO 3 − in real-world food samples is rather essential.…”

Iron Oxide Nanoparticle-Loaded Magnetic Cellulose Nanofiber Aerogel with Self-Controlled Release Property for Green Active Food Packaging

“…The incorporation of substances with antibacterial activity, antioxidant properties, and UV blocking performance is employed to delay food deterioration . Additionally, the detection of harmful substances or additives in food through discoloration or probe sensing represents a key advancement in food protection technology. , Among these innovations, green active food packaging has emerged as the primary solution to combat food degradation caused by harmful bacteria in recent years. Different from traditional packaging material, green active packaging can prevent the microbial degradation of foodstuffs by deliberately incorporating active agents that could inhibit bacterial growth through releasing into the headspace.…”