An international collaboration between Dalian University of Technology, China, Stanford University, USA, and The University of Queensland, Australia, has led to the development of a “dual-key-and-lock” ruthenium(II) complex probe for early cancer diagnosis and monitoring of cancer treatments.

Biomedical investigations have shown that excessive formaldehyde generation is possibly a critical factor for tissue cancerisation, cancer progression, and metastasis. The responsive molecular probe (Ru-FA) developed by the team is biocompatible, cell membrane permeable, and can detect lysosomal formaldehyde in live cells and tumours in human sera and mouse organs, making it an effective tool for formaldehyde detection in vitro and in vivo.

Ru-FA is a luminescence probe that “lights up” when it detects formaldehyde (first “key”) in an acidic microenvironment (second “key”). The luminescence intensity correlates to the formaldehyde concentration, allowing quantitative detection of formaldehyde in acidic microenvironments, such as cell lysosomes with pH 4.5–6.0. The team used ANFF-Q’s Leica SP8 confocal microscope to image the luminescent cancer cells. The results of this international collaborative project have been published in Journal of the American Chemical Society. For more details on the project, take a look at the case study.