Nonmetal-doped quantum dot-based fluorescence sensing facilitates the monitoring of environmental contaminants

Abstract

Environmental pollution is the main threatening factor to human health, survival and global sustainable development. Achieving rapid, sensitive detection of contaminants is extremely important for timely environmental pollution monitoring and treatment. Quantum dot (QD) probes have become a common method for the detection of contaminants. In particular, the development of QDs based on nonmetallic element-doped carbon materials QDs and other nonmetallic doped Si QDs, MoOx QDs, MoS₂ QDs, and MXene QDs provides a more convenient and effective means of detecting pollutants. However, a comprehensive summary of the application of nonmetal-doped QD probes for contaminant detection is still lacking. To address this issue, in the present work we mainly categorize different nonmetal-doped QDs into “top-down” and “bottom-up” strategies based on their preparation methods. QD probes based on nonmetal doping have unique optical properties, such as a narrow excitation spectrum, optical tunability, high fluorescence quantum yield (QY), and fluorescence stability. Fluorescence sensing technology can be realized through sensing mechanisms such as fluorescence/dynamic quenching, photoinduced electron transfer (PET), internal filtering effect (IFE), and fluorescence resonance energy transfer (FRET). Considering the ease of implementation, operation, and immediate response of fluorescence sensing technology, it has been widely used in research for the detection of environmental pollutants. We have found that fluorescence sensing technology based on nonmetal-doped QD probes can achieve rapid detection of pollutants (such as heavy metals in water or food, harmful nonmetallic ions, organic pesticides, and antibiotic residues), and its limit of detection (LOD) can reach the picomolar level for trace detection. In addition, the fluorescence sensing technology of nonmetallic QD probes can be combined with smart devices to realize real-time monitoring of pollutants. Our work provides additional strategies for developing nonmetal-doped QD probe-based detection of contaminants and advancing future environmental governance.