Colorimetric Sensing of Benzoyl Peroxide Based on the Emission Wavelength-Shift of CsPbBr3 Perovskite Nanocrystals

Li Zhang,Longjie You,Li Zhao,Zhiyong Guo,Xi Chen,Feiming Li,Yimeng Zhu,Linchun Zhang,Yaning Huang

doi:10.3390/chemosensors9110319

Abstract

Using the ionic salt characteristics of CsPbBr3 perovskite nanocrystals (CsPbBr3 NCs), the fluorescence wavelength of CsPbBr3−xIx NCs could be changed by the halogen exchange reaction between CsPbBr3 NCs and oleylammonium iodide (OLAM-I). Under the excitation of a 365 nm UV lamp and the increase of OLAM-I concentration, the content of iodine in CsPbBr3−xIx NCs increased, and the fluorescence emission wavelength showed a redshift from 511.6 nm to 593.4 nm, resulting in the fluorescence color change of CsPbBr3 NCs from green to orange-red. Since OLAM-I is a mild reducing agent and easily oxidized by benzoyl peroxide (BPO), a novel colorimetric sensing approach for BPO based on the fluorescence wavelength shift was established in this study. The linear relationship between the different wavelength shifts (Δλ) and the concentration of BPO (CBPO) is found to be in the range of 0 to 120 μmol L−1. The coefficient of alteration (R2) and the detection limit are 0.9933 and 0.13 μmol L−1 BPO, respectively. With this approach, the determination procedure of BPO in flour and noodle samples can be achieved in only a few minutes and exhibit high sensitivity and selectivity.

Highlights

In halide perovskite ABX3, X is the halogen anion (Cl−, Br−, or I− ), A is the monovalent cation Cs+ CH3 NH3 + (MA) or CH(NH2 )2 + (FA), and B is a divalent metallic cation, such as Pb2+, Sn2+, or Ge2+
Through the ratio of halogen ions in CsPbX3 NCs, the emission wavelength of their fluorescence spectra can be regulated to cover the whole visible region and produce significant color change from blue to red, which is very beneficial in colorimetric sensing with high visual sensitivity based on wavelength-shift
CsPbX3 NCs are unstable in water due to their intrinsic ionic salt properties, low surface energy generation, and limited ion radius tolerance factor, which creates challenges for their application in an aqueous medium

Summary

Introduction

In halide perovskite ABX3 , X is the halogen anion (Cl− , Br− , or I− ), A is the monovalent cation Cs+ CH3 NH3 + (MA) or CH(NH2 )2 + (FA), and B is a divalent metallic cation, such as Pb2+ , Sn2+ , or Ge2+. The discovery of halogen perovskites can be traced back to 1958 [1], they did not attract much attention until the study of Miyasaka et al using. MAPbI3 for solar cells in 2009; the research upsurge of lead halide perovskites (LHPs) attracted wide attention in relevant fields [2]. Chemosensors 2021, 9, 319 crystallization; and (b) LHPs have low exciton binding energy, resulting in low electronhole radiative. Energy, resulting in low electron-hole radiative recombinato lead halide perovskite (CsPbBr. nanocrystals researchers have turned their attention to lead halide perovskite binding energy and radiation recombination efficiency of LHPs by binding enhancing the quannanocrystals (CsPbBr3 NCs), in an attempt to improve the exciton energy and tum confined effect [14].

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