1 research outputs found
Dual-Emission of Lanthanide Metal–Organic Frameworks Encapsulating Carbon-Based Dots for Ratiometric Detection of Water in Organic Solvents
Nitrogen and sulfur codoped carbon-based
dots (N,S-CDs) with strong
blue light emission are encapsulated into red light-emitting europium
metal–organic frameworks (Eu-MOFs) to form two color light-emitting
nanohybrids (Eu-MOFs/N,S-CDs). In organic solvents, the encapsulated
N,S-CDs are aggregated and confined in the cavities of the Eu-MOFs,
exhibiting only a very weak photoluminescence (PL) signal. Therefore,
the nanohybrids show red light emission of the Eu-MOFs. Contrarily,
when the Eu-MOFs/N,S-CDs are dispersed in water, the encapsulated
N,S-CDs are released into solution while the red light emission of
the Eu-MOFs is quenched due to the effect of O–H oscillators.
The nanohybrids are used as the probe for the water content in organic
solvents. Take ethanol as an example; as the water content is increased
from 0.2 to 30%, the nanoprobe provides distinguishable PL color change.
The ratio of light intensity at 420 nm to that at 623 nm (<i>I</i><sub>420</sub>/<i>I</i><sub>623</sub>) increases
linearly with increasing water content in the range from 0.05 to 4%
with a low detection limit of 0.03%