High-fidelity carbon dots polarity probes: revealing the heterogeneity of lipids in oncology

Abstract

Polarity is an integral microenvironment parameter in biological systems closely associated with a multitude of cellular processes. Abnormal polarity variations accompany the initiation and development of pathophysiological processes. Thus, monitoring the abnormal polarity is of scientific and practical importance. Current state-of-the-art monitoring techniques are primarily based on fluorescence imaging which relies on a single emission intensity and may cause inaccurate detection due to heterogeneous accumulation of the probes. Herein, we report carbon dots (CDs) with ultra-sensitive responses to polarity. The CDs exhibit two linear relationships: one between fluorescence intensity and polarity and the other between polarity and the maximum emission wavelength. The emission spectrum is an intrinsic property of the probes, independent of the excitation intensity or probe concentration. These features enable two-color imaging/quantitation of polarity changes in lipid droplets (LDs) and in the cytoplasm via in situ emission spectroscopy. The probes reveal the polarity heterogeneity in LDs which can be applied to make a distinction between cancer and normal cells, and reveal the polarity homogeneity in cytoplasm.

Red emissive carbon dots as a fluorescent sensor for fast specific monitoring and imaging of polarity in living cells

“…30–33 These advantages make carbon quantum dots particularly suitable for the real-time detection and imaging of biological activity markers in multitudinous biological events, including polarity response. 34–37…”

“…[30][31][32][33] These advantages make carbon quantum dots particularly suitable for the real-time detection and imaging of biological activity markers in multitudinous biological events, including polarity response. [34][35][36][37] Among attractive carbon nanomaterials, uorescent carbon dots (CDs) of sizes less than 10 nm are widely used as promising uorescent sensors in biological imaging and as photodynamic therapy tools in consideration of their unique optical, chemical, and biological performances mentioned above as carbon-based nanoparticles. [38][39][40][41][42] However, despite these attractive properties, most reported CDs generally emit blue or green uorescence with low uorescence quantum yield and stability, which not only suffer from strong auto-uorescence and background interference in biological systems, but also cause radiation damage to tissues and cells.…”

Three birds, one stone: Disinfecting and turning waste medical masks into valuable carbon dots for sodium hydrosulfite and Fe3+ detection enabled by a simple hydrothermal treatment

“…In recent years, fluorescent carbon dots (CDs, a new type of carbon nanomaterial) have shown significant potential in various fields, such as sensing, detecting, environmental monitoring, biological imaging, nanoscopic imaging and cancer diagnosis, because of their excellent features of simple and low-cost synthetic methods, regulated optical characteristics, low toxicity, and superior photostability [13] , [14] , [15] , [16] , [17] , [18] , [19] . Various precursors such as organic molecules and biomass have been used to synthesize fluorescent CDs [20] , [21] , [22] .…”

Fluorescent probes based on acridine derivatives and their application in dynamic monitoring of cell polarity variation

“…[1][2][3][4] As complex parameters, polarity is affected by hydrogen bonds, dipoles, polarizability, etc., and viscosity is involved in various bioprocesses. [5][6][7][8] In addition, some diseases such as cancer and Alzheimer's disease have been authenticated to be related to polarity and viscosity. [9][10][11][12] Lipid droplets are the main storage sites for intracellular lipids.…”