Titanium carbides (Ti₃C₂), a new family of two-dimensional (2D) nanomaterials, have attracted extensive attention due to their unique structure and desirable physiochemical properties.

Group IV nanodots (NDs) mainly including carbon (C), silicon (Si), germanium (Ge) have aroused much attention as one type of important nanomaterials that are widely studied in optoelectronics, semiconductors, sensors and biomedicine-related fields owing to the low cost of synthesis, good stability, excellent biocompatibility, and some attractive newly emerged properties. In this review, the synthesis, surface engineering and application in bioimaging and biotherapy of group IV NDs are summarized and discussed. The recent progress in the rational synthesis and functionalization, specific therapy-related properties, together with in vivo and in vitro bioimaging are highlighted. Their new applications in biotherapy such as photothermal therapy (PTT) and photodynamic therapy (PDT) are illustrated with respect to C, Si and Ge NDs. The current challenges and future applications of these emerging materials in bioimaging and biotherapy are presented. This review provides readers with a distinct perspective of the group IV NDs nanomaterials for synthesis and surface engineering, and newly emerging properties related to applications in biomedicine.

The rapid advancement of thermal materials and fluorescence spectroscopy has extensively promoted the development of micro-scale fluorescence thermometry in recent years. Based on their advantages of fast response, high sensitivity, simple operation, high spatial resolution, and non-destructive detection, fluorescence thermometers have become powerful analysis tools used to sense temperature fluctuations through fluorescent signals, especially to accurately capture living cells via fluorescent signals and local temperature variations in living bodies, thus providing the most direct means for the in-depth understanding of biological processes in cells. Herein, we systematically categorize the currently reported fluorescence thermometers based on the aspects of fluorescence intensity and wavelength, reveal the intrinsic relationship between fluorescence (intensity and wavelength) and temperature response, expound the applications of fluorescence thermometers in the fields of chemical sensing and biomedicine, and analyze the challenges faced by current fluorescence thermometers based on fundamental problems and practical applications simultaneously, thus highlighting the future directions of fluorescence thermometers.