The potential application of quantum dots (QDs) as bioprobes is promising due to their quantum scale effects and special fluorescent properties. When compared with normal fluorescent materials, QDs have advantages including long-term photostability, higher intensity, tunable size, broad UV excitation profiles, and narrower emission spectra.1,2 These properties allow QDs to label different materials at the same time,3,4 contributing to their usefulness as qualitative and quantitative probes for multiplexed detection.5–7 QDs provide new approaches for real-time, high-sensitivity, and dynamic fluorescent imaging in DNA and protein detection as well as relevant biochips and biosensors.8–10 Tumors have cellular heterogeneity, which leads to different responses to drugs and the environment as well as the failure of cancer treatment.11,12 Therefore, it is important to study cancer cells’ cellular heterogeneity. With the single-cell array, we can micropattern cells as designed; so, we can focus on the individual behaviors and their reactions to the drugs, rather than that of the cell colony. As a result, we can have a better understanding of cellular heterogeneity. Combining single-cell arrays with QD probes, we can achieve multiplexed detection of the behaviors of individual cells and high-throughput drug screening.