Trypan Blue-Based Carbon Dots for Sensing of Al in Real Samples and Living Cells.

Aluminum is widely used in diverse fields of our daily life including maquillage, vaccine adjuvants, food packing, etc. Long-term aluminum exposure will lead to osteoporosis, Alzheimer's disease, and chronic renal failure. There still remains a need to develop low-cost, suitable, and rapid methods for the detection of Al. Herein, trypan blue-carbon dots (TB-CDs) were fabricated via a facile hydrothermal approach. The obtained TB-CDs were thoroughly analyzed by TEM, X-ray diffraction, FT-IR, XPS, UV-vis spectrophotometry, and fluorescence spectrophotometry. TB-CDs were spherical with a mean particle size of 2.9 nm and exhibited a high aqueous solubility with a fluorescence quantum yield of 6.37%. The obtained TB-CDs showed excellent photostability and relatively low cytotoxicity. The extent of fluorescence enhancement of TB-CDs was linearly related to the logarithmic concentration of Al. Thus, a fluorescence-on method was developed for fast and highly specific detection of Al within the range of 0.5 to 4 μmol L. The limit of detection was 0.2 μmol L. Furthermore, the established sensing platform was successfully utilized for Al determination in real samples and the intracellular imaging of Al. Owing to their convenience, low cost, and fast response, TB-CDs displayed promising potential in biochemical analysis and bioimaging fields.