Highly-fluorescent carbon dots grown onto dendritic silica nanospheres for anthrax protective antigen detection.

Direct synthesis of carbon dots on uniform mesoporous nanospheres is an ideal way to impart fluorescence properties to the nanomaterials and retain its original uniformity. Carbon dot-based nanospheres with high quantum yield (aqueous solution, 89.3%) were synthesized by the one-step hydrothermal treatment of sodium citrate and dendritic silica spheres grafted with N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane. Its excellent chemical properties such as fluorescence, stability, homogeneity and dispersion enable it to achieve a sensitive, specific, rapid and low-cost detection of anthrax protective antigen when used as a signal for immunochromatography.