In addition to the application in malignancy analysis, SERS tags have also displayed increasingly critical tasks in malignancy therapy. 16-18. Moreover, SERS tags have been endowed with multiple tasks by integrating imaging with additional functions (such as photothermal therapy (PTT) and photodynamic Angiotensin III (human, mouse) therapy (PDT)) for simultaneous analysis and treatment 19-21. Consequently, SERS tags display great potentials in medical applications. With this review, we will focus on state-of-the-art applications in biomedical with SERS tags. Starting with the building blocks of SERS tags, we expose the fabrication process and the design basic principle of SERS tags, followed by the topics in biomedical applications based on SERS tags. We 1st summarize the recent progress of biomarkers in biological fluids and cells recognized by SERS tags. Subsequently, we move the focus to the application of SERS tags for biomedical imaging ranging from cellular imaging to tumor imaging. Further, the fascinating applications of SERS tags Angiotensin III (human, mouse) in the medical center, including the delineation of tumor margins and the integration of analysis and therapy, are launched. Finally, we provide perspectives within the possible hurdles of SERS tags employed in long term clinical translation. Building blocks of SERS tags As a signal output resource for indirect detection, a SERS tag usually consists of a plasmonic nanoparticle core, a coating of Raman reporters, a protecting coating shell outside the Raman reporters, and focusing on ligands within the protecting shell. Plasmonic nanoparticle core Angiotensin III (human, mouse) has the mission to enhance the Raman signals, whose chemical composition, size, and shape significantly impact the overall performance of SERS tags. The enhanced Raman signal of the reporters on the surface of the plasmonic nanoparticle may indirectly reflect the amounts of analytes when the SERS tags are employed for bioanalysis. Due to the difficulty of biological samples, the structure that Raman reporters attached to the plasmonic core may become unstable; the protective coating appears to be essential. The outmost focusing on ligands are needed to endow SERS tags with the ability to detect biomolecules selectively. The typical preparation process of a SERS tag is definitely illustrated in Plan ?Scheme11. Open in a separate windowpane Plan 1 Building blocks and preparation process of a SERS tag. In general, to better use the SERS tag for biomedical applications, brightness is a critical factor that should be considered when designing a SERS tag. The brightness of the SERS tag is affected by the effect of SERS enhancement factor, the number of Raman reporters, and the molecular cross-section. To enhance the brightness, there are several principles to follow. First, we can improve the SERS enhancement factor of the plasmonic nanoparticle cores. Compared to the standard ones, plasmonic cores bearing intense hot spots have come into notice with enhanced enhancement factors, such as dimers, aggregates, gap-embedded cores, and porous cores. In addition, by modifying the Raman reporters, like choosing reporters with larger Raman cross-sections or increasing the effective quantity of reporter molecules, the brightness of SERS tags could also be improved. Moreover, in the past decades, eliminating background has become another fashion to improve the level of sensitivity of SERS tags by increasing their signal-to-background percentage (SBR). The SBR, defined Angiotensin III (human, mouse) as the level of the desired signal relative to the background signal, is the key element to realize the detection of low-abundance focuses on, especially in complicated samples. In this regard, different from the conventional nanotags that show multiple bands in the fingerprint region ( 1800 cm-1), Raman tags possess characteristic peaks in the so-called Raman-silent region (1800-2800 cm-1) have drawn the attention, where no Igf1r signals can be recognized for endogenous biomolecules, meaning zero background noise. To this end, molecules with chemical organizations, such as alkyne, azide, nitrile, deuterium, and metal-carbonyl have been used as Raman reporters to fabricate background-free SERS tags for bioanalysis and bioimaging. Additionally, to obtain reliable results for biomedical analysis, the uniformity and stability of SERS tags are another two important issues that should be considered cautiously. By employing liquid phases.