Metal ligand chromophores for bioassays

Bioassays are broadly defined as analytical methods that are used for the determination of the concentration and/or activity of an analyte in biological samples. The nature of analytes is diverse and varies from small ions, drug molecules, metabolites, to large protein molecules such as enzymes and antibodies. Due to the advanced development in optical spectroscopic and imaging instruments, and their convenience, fast response times, and excellent sensitivity, most bioassays involve optical detection such as absorption and fluorescence measurements. Photofunctional d- and f-block metal complexes make special contribution to the development of sensitive bioassays because they offer intriguing photophysical properties. For example, metal complexes show intense absorption in the UV and visible region, with the emission occurring at much lower energy; thus, the resulting large Stokes shift minimizes self-quenching of emission that is commonly observed in organic compounds. Also, the emission lifetimes are much longer than those of fluorescent organic dyes, allowing time-resolved spectroscopic and microscopy techniques. Additionally, many metal complexes are photostable, making it possible for the continuous detection and imaging of target analytes in real time. Furthermore, the usual redox-active property of metal complexes means that they can be exploited in ultrasensitive electrochemiluminescence detection. The review articles included in this topical collection will focus on the contemporary role of photofunctional metal complexes in the design of bioassays. The topical collection will be appealing to inorganic and analytical chemists, photochemists, cell biologists, chemical biologists, and medical scientists.


  • Kenneth Kam-Wing Lo

    Professor Kenneth Kam-Wing Lo is working as a Professor at Department of Chemistry of City University of Hong since 2011. He was one of the Chairs of the Gordon Research Conference Metals in Medicine 2018 and the Chair of the 23rd International Symposium on the Photochemistry and Photophysics of Coordination Compounds (ISPPCC 2019). He was awarded a Croucher Senior Research Fellowship from the Croucher Foundation in 2015. His research focus is on the development of intracellular sensors, photofunctional labels, bioimaging reagents, bioorthogonal probes, and activatable photosensitizers for photodynamic therapeutic applications.

  • Dr. Peter Kam-Keung Leung

    Dr. Peter Kam-Keung Leung obtained his BSc and PhD degrees at City University of Hong Kong in 2015 and 2021, respectively. He is currently working as a Postdoctoral Fellow under the supervision of Prof. Kenneth Lo. His research interests focus on the design of photofunctional transition metal complexes as bioorthogonal probes, peptide and protein tag substrates, and photocytotoxic agents.

Articles (6 in this collection)