https://www.selleckchem.com/products/Nolvadex.html 6% to 104.2%. The results demonstrated that the Fe3O4@NHCS modified electrode had the characteristics of high sensitivity, good selectivity and reliability. The recent rapid advances in the synthesis, functionalization and application of nanomaterials have enabled scientists to develop metal nanoclusters (MNCs) stabilized with a variety of scaffolds/protecting ligands including thiols, polymers, proteins, dendrimers and nucleic acids. Considering the unique optical, electronic and physical properties of MNCs, they have been successfully used for the tumor marker biosensing assays. In recent years, the ultrasensitive and accurate detection of tumor markers has been of critical importance for the screening or diagnosis of cancers at their early stages. Nanoclusters have revolutionized the design of biosensors and provided an opportunity for the selective and sensitive determination of tumor markers. Here, we review the synthesis, stabilization and promising applications of fluorescent MNCs, with particular focus on their potential for designing tumor marker biosensors. Finally, the current challenges and future perspectives on the emerging MNC-based biosensors are highlighted as well. Our intended audiences are the broader scientific communities interested in the nanomaterial-based biosensors, and our review paper will, hopefully, open up new horizons for those scientists who manipulae the biological properties of nanoclusters. This review is based on publications available up to January 2020. Carcinoembryonic antigen (CEA), as one of the common tumor markers, is a human glycoprotein involved in cell adhesion and is expressed during human fetal development. Since the birth of human, CEA expression is largely inhibited, with only low levels in the plasma of healthy adults. Generally, CEA will overexpressed in many cancers, including gastric, breast, ovarian, lung, and pancreatic cancers, especially colorectal cancer. A