Growth of carbon dots in nanoporous silica glasses for highly enhanced dual-wavelength emission.

Solid-state carbon dots (CDots) have great potential applications in photonics and optoelectronic devices due to their excellent optical properties, such as broad absorption bands, and tunable photoluminescence wavelengths. However, owing to the aggregation-induced quenching and thermal quenching effect, it is a challenge to achieve strong luminescent solid-state CDots with excellent thermal stability. Herein, solid-state CDots were designed and fabricated using a triple confinement nanoporous glass. The triple confinement in nanoporous glass by a highly rigid network, stable covalent bonding, and 3D spatial restriction efficiently inhibited the Föster resonance energy transfer of the CDots in the solid-state and highly confined the CDots in the nanopores and nanochannels of the nanoporous glass. The as-designed triple confined solid-state CDots exhibit dual emission wavelengths at 448 nm and 638 nm, 51 times enhanced photoluminescence intensity, and exceptional thermal stability up to 400 °C. This work provides design principles and a universal strategy to construct dual emission fluorescence materials with high photoluminescence intensity, and high thermal stability for promising applications.

Unveiling Hg-binding protein within black deposit formed on Golgi-Cox-stained brain neuron.

BACKGROUND: Golgi-Cox staining has been conventionally used for investigating neuronal development. After the brain tissue is subject to Golgi-Cox staining, black deposits are formed on the surface of the stained neurons because of mercuric sulfide, which does not show a fluorescence response under two-photon excitation. However, we unexpectedly observed fluorescence emitted by these black deposits during two-photon fluorescence measurements. Further, the in-depth of physical and chemical methods analysis revealed that the black deposits on the stained neurons are composed of Hg-binding proteins. METHODS: We studied black deposits present in the Golgi-Cox-stained mouse brain neurons using techniques such as multiple-photon microscopy, scan electron microscopy, micro-Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. RESULTS: The emitted fluorescence was because of the fluorescence groups of Hg-binding protein present within the Golgi-Cox deposits on the neuronal surface. CONCLUSIONS: The presence of Hg-binding proteins within black deposits on the surface of Golgi-Cox-stained neurons was proven for the first time. The novel interaction between the neurons and Hg2+ ions during Golgi-Cox staining help to understand the mechanism of Golgi-Cox staining.

Synthesis, crystal structure, self-assembly of C60 derivatives bearing rigid pyridine substituents.

Microstructures of fullerene derivatives formed via self-assembly strategy facilitate the versatile applications of these zero-dimensional molecules. However, the accurate elucidation of formation mechanism of fullerene microstructures is a challenge issue. A novel fullerene derivative 2 with rigid pyridine substituent was synthesized and characterized by X-ray crystallography. Using the strategy of liquid-liquid interfacial precipitation, self-assembly of 2 affords a micrometer-sized flowerlike and a discoid morphology. Based on the crystal packing of 2, the proper formation mechanism of different morphologies was proposed. Meanwhile, the photoelectrochemical properties of different morphologies of 2 was also unveiled.