Colorimetric Sensor for Measuring Bleaching Benzoyl Peroxide (BPO) Content in Wheat Flour Based on Perovskite CsPbBr3 Nanocrystal: A Preliminary Study

Abstract

Benzoyl peroxide (BPO) is one of the bleaching agents for flour that is widely used in food products, such as bread and noodles, which if consumed continuously can cause health problems. An excess of BPO in the body will cause vertigo, vomiting, neurasthenia, and a variety of diseases, resulting in serious damage to the liver and other organs. In this work, a colorimetric sensor using CsPbBr3 nanocrystal (NC) was studied to measure the BPO concentration in the solution. The halogen ion exchange reaction between CsPbBr3 NCs and iodine (I−) was carried out by adding oleylammonium iodide (OLAM-I) to the CsPbBr3 NC solution. The results show that the originally green emission of CsPbBr3 NC (515 nm) is turned into red-pink (660 nm) after addition with OLAM-I due to iodide ions exchange with bromide ions in CsPbBr3 NCs. The wavelength shift was occurred rapidly, only in 1 minute. The emission of CsPbBr3+OLAM-I (660 nm) solution was blue-shifted rapidly within 1-2 minutes after BPO addition. The magnitude of the emission wavelength shift proportional to the concentration of BPO concentration, with a higher concentration leads a higher wavelength shift (Δλ). Therefore, this wavelength shift can be used as rapid and real-time sensor for detecting BPO content in the real samples of white flour and noodles.