Carbon nanodots interference with lactate dehydrogenase assay in human monocyte THP-1 cells

Petra C Wright, Hu Qin, Martin MF Choi, Norman HL Chiu, Zhenquan Jia

Carbon nanodots (CD), a new class of carbon nanomaterials with sizes below 10 nm, have recently attracted wide attention due to their superiority in water solubility, chemical inertness, and resistance to photobleaching. As a result, CD has found important and wide applications in energy, catalysis, biological labeling, bioimaging and drug delivery. On the other hand, due to the lack of available toxicity data, there is a growing concern regarding the potential risks of CD. Hence, accurate assessment of the cytotoxicity of CD has become more important than ever before. The lactate dehydrogenase (LDH) assay is widely used to detect cytotoxicity of various nanoparticles including CD. Many recent studies used LDH assay to study the CD toxicity in various cells. However, these studies failed to further examine whether the CD were interfering with the LDH assay which would alter their findings.