Cellulose supported material for the development of eco-friendly sensors for the detection of SO₂.

In addition to the use of sulfur dioxide (SO₂) to prepare sulfuric acid, sulfur trioxide and various sulfites, SO₂ finds applications as a component of disinfectants, reducing agents, commercial bleaches, preservatives¹, and refrigerants. The use of SO₂ in the food industry as a preservative leads to a pressing need for the development of materials to control the amount of SO₂ used in beverages and dry fruits. Notably, if such amounts remain unchecked, significant health issues² can result. Various detectors to monitor the presence and concentration of SO₂ have been developed, but most of them have significant shortcomings, including the complexity of the measurement procedure, toxicity of materials used, and the time used for the measurement. Being mindful of the current limitations, we herein report the development of a new, cellulose-based detector for the detection of SO₂ which can detect SO₂ at concentrations below 100 ppm, which is much below the limit set by various health organizations. The other materials used for the development of the sensor include cyclodextrin and potassium permanganate (KMnO₄) which are non-toxic and do not cause any deleterious effects. The development of the cellulose-supported sensor is designed to work via a change in color in the presence of SO₂, which is visible to the naked eye and quantifiable using straightforward procedures. The sensor is developed to make it very user-friendly and requires no background knowledge prior to usage, which enables the use of the sensor by the general public, and the potential for increasing the control over SO₂ in commercially available foods and beverages.

(1) Fazio, T.; Warner, C. R. A Review of Sulphites in Foods: Analytical Methodology and Reported Findings. http://dx.doi.org/10.1080/02652039009373907 2009, 7 (4), 433–454. https://doi.org/10.1080/02652039009373907.

(2) A review of controlled human SO2exposure studies contributing to the US EPA integrated science assessment for sulfur oxides. Inhalation Toxicology, 23(1), 33–43 | 10.3109/08958378.2010.539290