Sulfhydryl-modulated CsPbBr3 nanocrystals as a fluorescent tongue for discrimination of formaldehyde releasers and parabens.

Adding preservatives to cosmetics have raised many concerns about health issues. Here, we propose a fluorescence sensor array for preservative discrimination based on two types of CsPbBr 3 nanocrystals (NCs) modified with two different thiol compounds (i.e., 6-mercapto-1-hexanol (6-MCH) and dithiothreitol (DTT)). The redox reaction between the sulphydryl of 6-MCH and DTT and the carbon oxygen double bonds of preservatives will enhance the fluorescence intensity, which is due to the depletion of superficially decorated DTT and 6-MCH at CsPbBr 3. By manipulating this mechanism, different preservatives generate unique fluorescence fingerprint responses through the diverse interactions between targets and two CsPbBr 3 NCs. Thus, two types of preservatives, including four formaldehyde releasers and three parabens, were well distinguished at low concentration using linear discriminant analysis (LDA) by this sensor array. Remarkably, preservative identification in hand cream further proves the array's practical applicability in complex environment. • We propose a fluorescence sensor array for preservative discrimination based on sulphydryl-functionalized CsPbBr 3 NCs. • The redox reaction between the sulphydryl and the C O of preservatives enhance the fluorescence intensity. • Unique fluorescence fingerprints can be differentiated using linear discriminant analysis • Two types of preservatives, including 4 formaldehyde releasers and 3 parabens, were distinguished at low concentration. [ABSTRACT FROM AUTHOR]