A QR code-integrated chromogenic paper strip for detection of hydrogen peroxide in aqueous samples

Hydrogen peroxide (H₂O₂) is commonly used as a preservative, disinfectant, bleach, and oxidizing agent. The prolonged consumption of H₂O₂ adulterated milk is harmful to human health when consumed in the diet. Exposure to H₂O₂ can lead to oxidative stress, cell damage and tissue injury. Due to the potential adverse effects, the use of hydrogen peroxide is regulated in certain applications, such as in food, water treatment plants and medical products. Several methods are available for the detection of H₂O₂ in various matrices. Here, a method and QR code-integrated chromogenic paper strip for the detection of H₂O₂ in aqueous samples has been developed. The spectrophotometric method showed an LOD and LOQ of 0.00087 ± 8.70 ×10^-5% (v/v) and 0.0037 ± 0.0003% (v/v), respectively. The paper-based chromogenic strip prepared by immobilizing recognition solution onto a QR code was able to detect 0.0005% v/v of H₂O₂ in aqueous samples. The QR integrated chromogenic paper strip sensors can serve as a useful tool for consumers, regulatory agencies, and the food industry to assess food quality and authenticity.