Simple Colorimetric Assay for Sulfite Detection

Sulfites are known allergens pervasive in food and wine consumer products that cause difficulty breathing, skin rashes, and in extreme cases, death. They are added in the form of sulfur dioxide (SO2) for its antimicrobial properties and to prevent food spoilage. The SO2 does not remain in the molecular form and is converted to sulfite (SO32-) and bisulfite (HSO3-). While the beer, wine, and food industries test for SO2  levels, they do not typically test for SO32- and HSO3- levels in their products, since there is no simple, accurate, and affordable test for sulfites in aqueous solution.    The present invention provides for an allergen test that is rapid, accurate, precise, and affordable. While anion sensors have made significant advances, relatively few selective, naked eye, water-soluble sensors exist. Here, a novel anion sensor displays a substantial color loss upon addition of sodium sulfite in pure water. The sensor shows a ten percent decrease in the lowest absorption band upon the addition of 0.84 ppm sodium sulfite. In addition to its capabilities as a sensor, the molecule provides an ability to label food, wine, and cider products with the actual sulfites concentration.


  • Does not require (like other test strips currently available) pH adjustment with hazardous sulfuric acid or sodium hydroxide, the use of a pH meter, flammable activated charcoal.
  • More accurate, reproducible, and precise (i.e. standard deviation = 0.01) than other test strips.
  • Test is rapid, affordable, and accurate within a large range of sulfites concentration, from 0.84 ppm to over 10,000 ppm.


Binghamton University RB526

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