Multiresponsive White-Light Emitting Aerogel Prepared with Codoped Lanthanide/Thymidine/Carbon Dots

Abstract

Aerogels hold great promise as a lightweight replacement in materials fields. Dynamic fluorochromic aerogels that possess reversible stimuli responsiveness have been particularly attractive recently for new design opportunities in practical solid-state lighting and wide applications in advanced sensors/probe. In this study, we report a reversibly multiresponsive white-light-emitting (WLE) aerogel prepared with codoped lanthanide, thymidine, and carbon dots. By precisely modulating the stoichiometric ratio of lanthanide complexes and carbon dots, broad-spectrum output from purple to red is obtained, including pure white light (CIE (0.33, 0.32)). The freeze-drying process contributes to the elimination of hydration between water molecules and lanthanide ions, further preventing the quenching of lanthanide luminescence and preserving the high quantum yield (47.4%) of our aerogel. Moreover, the dynamic coordination bond between lanthanide (europium and terbium) and thymidine endows the aerogel with reversible responsiveness upon five different stimuli, including halide anions, metal ions, pH, temperature, and humidity. We envision that our WLE aerogel has considerable potential for use in various fields such as display devices, advanced sensors, and environmentally friendly probes where multiresponsiveness is required.

Preparation and Applications of Carbon‐Based Fluorescent Nanothermometers

“…Nevertheless, as the temperature rises, the photoluminescence (PL) intensity of the most temperature‐sensitive carbon‐based materials changes, enabling temperature detection. [ 23–25,79–99 ] In general, the temperature‐response mechanism of carbon‐based fluorescent materials mainly consists of the change in surface states and molecular states, thermally activated nonradiative trapping, spectral shift, and broadening of the zero‐phonon line (ZPL). [ 5–18 ]…”

“…In recent years, fluorescent carbon‐based materials, represented by fluorescent NDs, fluorescent GQDs, fluorescent P‐dots, and fluorescent CDs, have been extensively investigated for the temperature measurement of cells and other living and nonliving organisms. [ 79–98 ] Based on the different fluorescence characteristics, the carbon‐based thermometers can be classified into two types: single‐wavelength fluorescent carbon‐based thermometers and dual‐wavelength fluorescent carbon‐based thermometers.…”

“…Moreover, this multidoped material can respond to changes of halide anions, metal ions, pH value, temperature, and humidity simultaneously (Figure 13C). [ 82 ] By mixing Eu 3+ , cytidine, fluorescein, and CDs via a one‐pot method, Xue's team prepared a white light‐emitting hydrogel. The hydrogel can measure the temperature in the range of 25–80 °C, as well as pH value and Fe 3+ content.…”

“…These advantages make the carbon‐based thermometers have plenty of applications, especially in non‐contact temperature detection for biology and biomedicine. [ 79–98 ] The carbon‐based thermometers can be divided into two wide categories based on their output signals: single emission and dual emission.…”

“…They show the following advantages: high optical absorptivity, adjustable fluorescent emission, chemical stability, well biocompatibility, and low toxicity. [ 5–99 ] Given these superior properties, they have been extensively discussed in bioimaging devices, biosensors, catalysts, photovoltaic devices, as well as fluorescent nanothermometers for spatially resolved temperature ( Figure ). [ …”