Simple and accurate quantification of quantum yield at the single-molecule/particle level.

Quantum yield represents one of most fundamental and important properties of photoluminescent materials and eventually determines the suitability of materials for the applications in optical devices, analysis, biosensing, and fluorescence imaging. Despite that a variety of methods have been developed to measure the quantum yield, its accurate quantification still remains a great challenge. Here, we develop a new approach with the capability to quantify the quantum yield at the single-molecule/particle level. The quantum yield obtained by the single-molecule/particle detection is in agreement with that obtained by the conventional optical method. Importantly, this method can accurately measure not only the quantum yield of organic dyes but also that of quantum dots and can be further extended to measure the quantum yield of various fluorescent materials, including the nontransparent sample whose quantum yield is impossible to obtain using the conventional optical method.