Dyes Encapsulated Nanoscale Metal–Organic Frameworks for Multimode Temperature Sensing with High Spatial Resolution

Abstract

Luminescent nanothermometers working with high resolution and multiple optical signals are a powerful tool for complex analysis with high accuracy and selectivity. Herein, we describe a novel strategy, for the first time, by encapsulating two types of luminescent dyes (4-Mu and Flu) into the pores of a nanoscale metal–organic framework (MOF) ZIF-8 for multimode temperature sensing. When the temperature rises, the maximum emission wavelength (λmax) of dye 4-MU in ZIF-8⊃4-MU&Flu redshifts, and the emission ratio (I Flu/I 4‑MU) of Flu and 4-MU in ZIF-8⊃4-MU&Flu shows good linear response to temperature, which indicate the high sensitivity of the nanothermometer with multimode temperature readout (S m = 0.62% K–1 at 240 °C). Remarkably, the uniform nanoscale size distribution and good thermal stability of the nanosized MOF⊃dyes composites enable it to perform multimode temperature sensing with high spatial resolution, which is demonstrated by the temperature mapping. Therefore, this material shows a more-reliable temperature indication by utilizing the multiparameter readout and an excellent temperature distribution with high spatial resolution.

Hydrogen bonding-mediated assembly of carbon dot@Zr-based metal organic framework as a multifunctional fluorescence sensor for chlortetracycline, pH and temperature detection

“…The maximum value of S r for CDs@UiO-66(COOH) 2 -50 was calculated to be 0.82% °C −1 at 10 °C, which shows a higher sensitivity to temperature changes in comparison to the other optical thermometers reported previously (Table 2). 48,50–54 Additionally, the temperature resolution (δ T ) is another key parameter for evaluating the sensitivity of optical thermometers for practical applications, which can be calculated according to the following eqn (5):in which the signal-to-noise ratio of the fluorescence spectrometer used is 16 000 : 1, that is to say, the value of δ Δ / Δ is about 0.0125%. 37 The calculated δ T value of CDs@UiO-66(COOH) 2 -50 was estimated better than 0.034 °C over the entire measured temperature range (10–80 °C) (Fig.…”

“…The maximum value of S r for CDs@UiO-66(COOH) 2 -50 was calculated to be 0.82% 1C À1 at 10 1C, which shows a higher sensitivity to temperature changes in comparison to the other optical thermometers reported previously (Table 2). 48,[50][51][52][53][54] Additionally, the temperature resolution (dT) is another key parameter for evaluating the sensitivity of optical thermometers for practical applications, which can be calculated according to the following eqn (5):…”

Nanoscale Metal−Organic Frameworks and Their Nanomedicine Applications

“…Nanoscale metal-organic frameworks (NMOFs), a peculiar class of metal-organic self-assembly materials, integrate the merits of beneficial property of bulk MOFs and nanomaterials. First, highly porous and large channels enable NMOFs loading imaging agents and/or therapeutic preparations efficiently meanwhile by covalent attachment the construction units—whether metal ions/cluster or organic ligands—both can be used to payload imaging cargoes and/or drugs ( Chen D et al, 2017 ; Hang et al, 2017 ; Yin et al, 2017 ; Cao et al, 2021 ). For example, by choosing construction units or decorating imaging components, NMOFs-based diagnostic and therapeutic agents have been extensively developed and used for magnetic resonance imaging (MRI) ( Chowdhuri et al, 2016 ), computed tomography (CT) ( Tian et al, 2015 ), positron emission tomography (PET) ( Zhao et al, 2016a ), and optical imaging ( Yang S P et al, 2017 ).…”

Our journey of developing dual‐emitting metal‐organic framework‐based fluorescent sensors

“…Apart from these approaches, dual emission generated from two encapsulated dyes, [32] two-photon fluorescence and second harmonic generation (SHG) signal, [33] near infrared Nd/Yb, [16][17] packaged carbon dots and dye, [25] mixed organic lumophores [20] were proposed by other scientists. Film thermometers [34] and nanothermometers [35] are also the focus of current research.…”