Inhibitory effect of zinc oxide nanorod arrays on breast cancer cells profiled through real‐time cytokines screening by a single‐cell microfluidic platform

Abstract Zinc oxide nanorods have been extensively studied for the specific killing of breast cancer (BC) cells, and their killing mechanism and anticancer effects have been initially demonstrated. However, systematic studies at the single‐cell level are still necessary to explore cellular functions in detail. In this work, a hydrothermal method was used to synthesize zinc oxide nanorod arrays (ZnO NRs). Their effect on BC cells was demonstrated at single‐cell resolution for the first time through microfluidic chips and a single‐cell analysis platform. The inhibitory effects of ZnO NRs were observed. First, ZnO NRs suppressed cell proliferation and migration abilities. Moreover, Interferon‐γ, Tumor Necrosis Factor‐α, and Granzyme B in BC cells turned out to be antitumor instead of tumorigenic under ZnO NRs stimulation. Furthermore, ZnO NRs inhibition altered cellular functions and thus weakened intercellular and intercluster correlations. More importantly, MDA‐MB‐231 cells (strongly metastatic) showed much greater resistance to ZnO NRs than MCF‐7 cells (nonmetastatic). The experiments complemented the findings at the single‐cell level and provided a more comprehensive consideration of the potential risks and applications of ZnO NRs in breast cancer therapy, which is of great importance for biomedical research on nanomaterials

A Sensitive and Portable Double-Layer Microfluidic Biochip for Harmful Algae Detection

Harmful algal blooms (HABs) are common disastrous ecological anomalies in coastal waters. An effective algae monitoring approach is important for natural disaster warning and environmental governance. However, conducting rapid and sensitive detection of multiple algae is still challenging. Here, we designed an ultrasensitive, rapid and portable double-layer microfluidic biochip for the simultaneous quantitative detection of six species of algae. Specific DNA probes based on the 18S ribosomal DNA (18S rDNA) gene fragments of HABs were designed and labeled with the fluorescent molecule cyanine-3 (Cy3). The biochip had multiple graphene oxide (GO) nanosheets-based reaction units, in which GO nanosheets were applied to transfer target DNA to the fluorescence signal through a photoluminescence detection system. The entire detection process of multiple algae was completed within 45 min with the linear range of fluorescence recovery of 0.1 fM–100 nM, and the detection limit reached 108 aM. The proposed approach has a simple detection process and high detection performance and is feasible to conduct accurate detection with matched portable detection equipment. It will have promising applications in marine natural disaster monitoring and environmental care