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Multiple Defect‐Induced High‐Resolution Near‐Infrared Mechanoluminescent Materials for Non‐Destructive Detection of Blood Glucose and Lipids

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Advanced Materials
Authors:
Sheng Wu at South China Normal University
Sheng Wu
Guangyu Zhou
Guangyu Zhou
Guangyu Zhou
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Yafen Wu
Yafen Wu
Yafen Wu
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Puxian Xiong at The University of Hong Kong
Puxian Xiong
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Abstract and Figures

Mechanoluminescence (ML) materials, known for their ability to convert mechanical energy into light, are increasingly recognized for their potential applications, such as in intelligent stress sensing, in vivo bioimaging, and stress non‐destructive monitoring. However, the low signal‐to‐noise ratio (SNR) and narrow‐band emission of single‐defect‐induced ML materials usually limit their biological‐related practical applications. Here, these limitations will be addressed by modulating the microstructure evolution in Y3Ga3MgSiO12:Cr³⁺ through the [Si⁴⁺+Mg²⁺] → [Ga³⁺+Ga³⁺] chemical substitution strategy. Density functional theory (DFT) calculation reveals the defect types and dynamic charge migration processes. In addition, Y3Ga3MgSiO12: Cr³⁺ with continuously distributed “shallow‐deep” defects (0.68–1.61 eV) can avoid persistent luminescence (PersL) and bright‐field environment interference. Herein, such high SNR near‐infrared broadband ML emission may provide a reliable way for high‐quality biological non‐destructive sensing and detection. Finally, benefiting from the different absorption of ML signals in glucose/lipid, one may find a novel non‐invasive blood glucose/lipid testing technology in patients.
a,b) XRD patterns of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0–10.0%) and amplified diffraction peaks. c) Time‐resolved PL spectra of Y3Ga3MgSiO12:1.0% Cr³⁺. d) 2D time‐resolved spectra of Y3Ga3MgSiO12:1.0%Cr³⁺. e) XRD refinement patterns of Y3Ga3MgSiO12:1.0%Cr³⁺. f) Lattice constant of Y3Ga3MgSiO12:xCr³⁺ (x = 0.0‐10.0%). g) XPS of Y3Ga3MgSiO12: 1.0% Cr³⁺ and high‐resolution spectra of Cr³⁺ ions. h) EPR spectra of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0‐10.0%). i–o) SEM image, elemental mapping images of Y3Ga3MgSiO12: 1.0%Cr³⁺.
a,b) XRD patterns of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0–10.0%) and amplified diffraction peaks. c) Time‐resolved PL spectra of Y3Ga3MgSiO12:1.0% Cr³⁺. d) 2D time‐resolved spectra of Y3Ga3MgSiO12:1.0%Cr³⁺. e) XRD refinement patterns of Y3Ga3MgSiO12:1.0%Cr³⁺. f) Lattice constant of Y3Ga3MgSiO12:xCr³⁺ (x = 0.0‐10.0%). g) XPS of Y3Ga3MgSiO12: 1.0% Cr³⁺ and high‐resolution spectra of Cr³⁺ ions. h) EPR spectra of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0‐10.0%). i–o) SEM image, elemental mapping images of Y3Ga3MgSiO12: 1.0%Cr³⁺.
… 
a) DRS of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0‐10.0%). b) Plots of [F(R∞)*hν]² versus energy (eV) (x = 0.0 and 1.0%). c) Tanabe‐Sugano energy level diagram for Cr³⁺ ions. d,e) PLE/PL spectra of Y3Ga3MgSiO12: xCr³⁺ (x = 1.0%‐10.0%). f) PL intensity/FWHM/Emission peak position curves with Cr³⁺ concentration. g,h) Fluorescence lifetime decay curves Y3Ga3MgSiO12: xCr³⁺ (x = 1.0%‐10.0%). i) PersL decay curves for different excitation wavelengths. j) PersL excitation spectra and PLE spectra. k,l) PersL decay curves and plots of time versus intensity inverse for different concentrations.
a) DRS of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0‐10.0%). b) Plots of [F(R∞)*hν]² versus energy (eV) (x = 0.0 and 1.0%). c) Tanabe‐Sugano energy level diagram for Cr³⁺ ions. d,e) PLE/PL spectra of Y3Ga3MgSiO12: xCr³⁺ (x = 1.0%‐10.0%). f) PL intensity/FWHM/Emission peak position curves with Cr³⁺ concentration. g,h) Fluorescence lifetime decay curves Y3Ga3MgSiO12: xCr³⁺ (x = 1.0%‐10.0%). i) PersL decay curves for different excitation wavelengths. j) PersL excitation spectra and PLE spectra. k,l) PersL decay curves and plots of time versus intensity inverse for different concentrations.
… 
a) Schematic diagram of the production process of ML film. b) ML spectra (Force = 40 N) of Y3Ga3MgSiO12: xCr³⁺ (x = 1.0%‐10.0%). c) 3D ML spectra of Y3Ga3MgSiO12: Cr³⁺ as a function of time and stress. d) ML spectra of Y3Ga3MgSiO12:1.0% Cr³⁺ under different stress magnitudes. e) Stability and repeatability testing of Y3Ga3MgSiO12:1.0% Cr³⁺ under constant stress for 25 cycles.
a) Schematic diagram of the production process of ML film. b) ML spectra (Force = 40 N) of Y3Ga3MgSiO12: xCr³⁺ (x = 1.0%‐10.0%). c) 3D ML spectra of Y3Ga3MgSiO12: Cr³⁺ as a function of time and stress. d) ML spectra of Y3Ga3MgSiO12:1.0% Cr³⁺ under different stress magnitudes. e) Stability and repeatability testing of Y3Ga3MgSiO12:1.0% Cr³⁺ under constant stress for 25 cycles.
… 
a) ML intensity curve of 4 cycle tests. b) Pers‐ML luminescent photographs and 3D spectra of Y3Ga3MgSiO12:1.0% Cr³⁺. c) ML spectra of Y3Ga3MgSiO12:1.0% Cr³⁺ at different temperatures. d) Normalized ML intensity at different temperatures. e) ML spectra of Y3Ga3MgSiO12: 1.0% Cr³⁺ at 200 °C for different time. f) Normalized ML intensity at 200 °C at different time of standing treatment. g) ML spectra of Y3Ga3MgSiO12: 1.0% Cr³⁺ co‐doped with rare earth ions.
a) ML intensity curve of 4 cycle tests. b) Pers‐ML luminescent photographs and 3D spectra of Y3Ga3MgSiO12:1.0% Cr³⁺. c) ML spectra of Y3Ga3MgSiO12:1.0% Cr³⁺ at different temperatures. d) Normalized ML intensity at different temperatures. e) ML spectra of Y3Ga3MgSiO12: 1.0% Cr³⁺ at 200 °C for different time. f) Normalized ML intensity at 200 °C at different time of standing treatment. g) ML spectra of Y3Ga3MgSiO12: 1.0% Cr³⁺ co‐doped with rare earth ions.
… 
a) TL glow curves of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0%‐10.0%). b) Gaussian fitting TL glow curve of Y3Ga3MgSiO12: 1.0% Cr³⁺. c) TL glow curves of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0%‐10.0%) at different heating rates. d) The curve of Ln (Tm²/β) as a function of 1/(kB/Tm). e) Y3Ga3MgSiO12: 1.0% Cr³⁺ TL glow curves at different excitation temperatures. f) Analysis of the initial rise of the TL glow curve. g) TL glow curves of Y3Ga3MgSiO12: 1.0% Cr³⁺ under different friction time of 0 (green), 5 (blue), and 10 min (red). All samples were irradiated with 254 nm UV light for 10 min and then settled for 60 min. h) EPR spectra of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0%‐10.0%) regarding g‐factor. i) High‐resolution XPS spectra of O 1s with diffident Cr³⁺ content. j) Schematic diagram of defect formation. k) Y3Ga3MgSiO12: 1.0% Cr³⁺ potential PL, PersL and ML mechanism diagram.
+3
a) TL glow curves of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0%‐10.0%). b) Gaussian fitting TL glow curve of Y3Ga3MgSiO12: 1.0% Cr³⁺. c) TL glow curves of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0%‐10.0%) at different heating rates. d) The curve of Ln (Tm²/β) as a function of 1/(kB/Tm). e) Y3Ga3MgSiO12: 1.0% Cr³⁺ TL glow curves at different excitation temperatures. f) Analysis of the initial rise of the TL glow curve. g) TL glow curves of Y3Ga3MgSiO12: 1.0% Cr³⁺ under different friction time of 0 (green), 5 (blue), and 10 min (red). All samples were irradiated with 254 nm UV light for 10 min and then settled for 60 min. h) EPR spectra of Y3Ga3MgSiO12: xCr³⁺ (x = 0.0%‐10.0%) regarding g‐factor. i) High‐resolution XPS spectra of O 1s with diffident Cr³⁺ content. j) Schematic diagram of defect formation. k) Y3Ga3MgSiO12: 1.0% Cr³⁺ potential PL, PersL and ML mechanism diagram.
… 
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RESEARCH ARTICLE
www.advmat.de
Multiple Defect-Induced High-Resolution Near-Infrared
Mechanoluminescent Materials for Non-Destructive
Detection of Blood Glucose and Lipids
Sheng Wu, Guangyu Zhou, Yafen Wu, Puxian Xiong,* Binli Xiao, Zhiyao Zhou, Yao Xiao,
Peishan Shao, Shouping Wang, Zhigang Shao, Yinzhen Wang,* and Feifei Wang*
Mechanoluminescence (ML) materials, known for their ability to convert
mechanical energy into light, are increasingly recognized for their potential ap-
plications, such as in intelligent stress sensing, in vivo bioimaging, and stress
non-destructive monitoring. However, the low signal-to-noise ratio (SNR)
and narrow-band emission of single-defect-induced ML materials usually limit
their biological-related practical applications. Here, these limitations will be
addressed by modulating the microstructure evolution in Y3Ga3MgSiO12:Cr3+
through the [Si4++Mg2+]→[Ga3++Ga3+] chemical substitution strategy. Den-
sity functional theory (DFT) calculation reveals the defect types and dynamic
charge migration processes. In addition, Y3Ga3MgSiO12:Cr
3+with contin-
uously distributed “shallow-deep” defects (0.68–1.61 eV) can avoid persistent
luminescence (PersL) and bright-field environment interference. Herein,
such high SNR near-infrared broadband ML emission may provide a reliable
way for high-quality biological non-destructive sensing and detection. Finally,
benefiting from the different absorption of ML signals in glucose/lipid, one may
find a novel non-invasive blood glucose/lipid testing technology in patients.
1. Introduction
According to incomplete statistics from the World Health Orga-
nization, the global prevalence of three highs (hyperglycemia,
S. Wu, G. Zhou, B. Xiao, Z. Zhou, Z. Shao, Y. Wang
Guangdong Basic Research Center of Excellence for Structure and
Fundamental Interactions of Matter
Guangdong Provincial Key Laboratory of Quantum Engineering and
Quantum Materials
Guangdong-Hong Kong Joint Laboratory of Quantum Matter
Frontier Research Institute for Physics
School of Physics
South China Normal University
Guangzhou 510006, China
E-mail: agwyz@aliyun.com
Y. Wu , S. Wang
Department of Anesthesiology;
Guangdong Provincial Key Laboratory of Major Obstetric Diseases; Guang-
dong Provincial Clinical Research Center for Obstetrics and Gynecology;
The Third Afliated Hospital, Guangzhou Medical University
Guangzhou 510000, China
The ORCID identification number(s) for the author(s) of this article
can be found under https://doi.org/10.1002/adma.202408508
DOI: 10.1002/adma.202408508
hyperlipidemia and hypertension) exceeds
1.8 billion, and they are endocrine dis-
eases. Currently, the most effective treat-
ment for people with hyperglycemia is to
control blood sugar concentrations through
frequent testing and injection of drugs,
thereby reducing or alleviating complica-
tions caused by hyperglycemia. However,
the method of testing blood sugar mainly
involves drawing blood from the body for
biochemical testing and analysis, which
is invasive to the body and brings pain
and inconvenience to the patient. There-
fore, non-invasive NIR spectrum blood
glucose detection technology has received
great attention. The technology measures
blood sugar levels in the blood by analyz-
ing spectral signals of infrared lights that
pass through or are absorbed by body tis-
sue. Its significances are: 1) Reducing the
pain of daily blood collection and mea-
surement, and improving the quality of
life of patients. 2) Increasing the number
of measurements, improve the accuracy of blood sugar control,
and reduce the risk of complications. 3) Its measurement meth-
ods and principles can be applied to the detection of other blood
components. Currently, the more effective band is the infrared
P. Xiong, F. Wang
Department of Electrical and Electronic Engineering
The University of Hong Kong
Hong Kong 999077, China
E-mail: pxxiong@hku.hk;feifwang@hku.hk
Y. Xiao, P. Shao
Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied
Techniques
Guangdong Engineering Technology Research and Development Center of
Special Optical Fiber Materials and Devices
State Key Laboratory of Luminescent Materials and Devices
South China University of Technology
Guangzhou 510640, China
F. Wang
Materials Innovation Institute for Life Sciences and Energy (MILES)
The University of Hong Kong
Hong Kong 999077, China
Adv. Mater. 2024, 2408508 © 2024 Wiley-VCH GmbH
2408508 (1 of 16)
... Surprisingly, by doping Cr 3+ , more electronic states can be introduced at the Fermi level of the electronic structure, an electronic bridge between Cr 3+ →Nd 3+ can be constructed, and the door to the near-infrared ML of Nd 3+ ions can be opened to achieve high energy transfer efficiency (Figure 7b). Finally, by utilizing the NIR luminescence characteristics of Cr 3+ /Nd 3+ ions, ultra-wideband ML emission in the NIR 1→2 region is achieved, which has the potential for biological imaging (Figure 7c) [23,24] . ...
Regulating Broadband Near‐Infrared Mechanoluminescence via Energy‐Level Engineering for Potential Biomechanical Imaging
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Near-infrared mechanoluminescent (NIR ML) materials have attracted attention due to their advantages, such as in situ and real-time monitoring of biomechanical information in vivo. However, most ML materials are focused on the Ultraviolet-visible light range, which limits their potential applications in the biological field. In this work, a broadband NIR ML material Ca2YGa3Ge2O12: 0.10Cr3+ (CYGGG: 0.10Cr3+) was successfully prepared by chemical co-substitution and Cr3+ heavy doping. Density Functional Theory (DFT) calculations were used to determine the type of defects in the material, and the composite defects formed by interstitial oxygen (iO′′) and antisite defects (CaY′ - YCa°) mostly dominate NIR ML. Cr3+ ions act as electronic bridges to regulate energy levels, becoming the key to turning on the Nd3+ ion’s NIR ML. Finally, based on the excellent ML properties of CYGGG: 0.10Cr3+ and CYGGG: 0.10Cr3+, 0.01Nd3+, the ML composites can penetrate pork tissues of different compositions/thicknesses under stress loads. Potentially, this work tries to realize biological tissue stress imaging, providing a new way for the biological application of NIR ML materials.
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The near‐infrared (NIR) persistent luminescence (PersL) materials have attracted widespread attention owing to the unique self‐sustained light with good penetrability. Currently, most of the reported NIR PersL materials are activated by Cr³⁺. Considering the potential toxicity of chromium ions, there is an urgent requirement to explore the Cr³⁺‐free NIR phosphors. Herein, a novel NIR phosphor Sr2LuSbO6:Fe³⁺ (SLSO:Fe³⁺) is prepared and its luminescence properties are systematically studied. The Fe³⁺‐activated Sr2LuSbO6 exhibits a long‐wavelength NIR emission band centered at 890 nm with a 110 nm full‐width at half maximum (FWHM), and its PersL can last over 18 h. The phosphor shows excellent PersL stability even after being dispersed in solutions of different environments for 7 days. Furthermore, the PersL emitted by the phosphor can penetrate the 2 cm thickness beef, evidencing its good NIR PersL penetration property. This work provides a novel NIR PersL materials based on Fe³⁺ luminescence for technological applications and also contributes to accelerate the development of new‐generation Fe³⁺‐doped NIR PersL phosphor toward versatile applications.
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Mechanoluminescence (ML) materials are featured with the characteristic of “force to light” in response to external stimuli, which have made great progress in artificial intelligence and optical sensing. However, how to effectively enable ML in the material is a daunting challenge. Here, a Lu3Al2Ga3O12:Cr³⁺ (LAGO: Cr³⁺) near infrared (NIR) ML material peaked at 706 nm is reported, which successfully realizes the key to unlock ML by the lattice‐engineering strategy Ga³⁺ substitution for Al³⁺ to “grow” oxygen vacancy (Ov) defects. Combined with thermoluminescence measurements, the observed ML is due to the formation of defect levels and the ML intensity is proportional to it. It is confirmed by X‐ray photoelectron spectroscopy and electron paramagnetic resonance that such a process is dominated by Ov, which plays a crucial role in turning on ML in this compound. In addition, potential ML emissions from ⁴T2 and ²E level transitions are discussed from both experimental and theoretical aspects. This study reveals the mechanism of the change in ML behavior after cation substitution, and it may have important implications for the practical application of Ov defect‐regulated turn‐on of ML.
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Near‐Infrared Dual‐Modal Sensing of Force and Temperature in Total Knee Replacement Using Mechanoluminescent Phosphor of Sr3Sn2O7: Nd, Yb
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Knee replacement surgery confronts challenges including patient dissatisfaction and the necessity for secondary procedures. A key requirement lies in dual‐modal measurement of force and temperature of artificial joints during postoperative monitoring. Here, a novel non‐toxic near‐infrared (NIR) phosphor Sr3Sn2O7:Nd, Yb, is designed to realize the dual‐modal measurement. The strategy is to entail phonon‐assisted upconversion luminescence (UCL) and trap‐controlled mechanoluminescence (ML) in a single phosphor well within the NIR biological transmission window. The phosphor is embedded in medical bone cement forming a smart joint in total knee replacements illustrated as a proof‐of‐concept. The sensing device can be charged in vitro by a commercial X‐ray source with a safe dose rate for ML, and excited by a low power 980 nm laser for UCL. It attains impressive force and temperature sensing capabilities, exhibiting a force resolution of 0.5% per 10 N, force detection threshold of 15 N, and a relative temperature sensitive of up to 1.3% K⁻¹ at 309 K. The stability against humidity and thermal shock together with the robustness of the device are attested. This work introduces a novel methodological paradigm, paving the way for innovative research to enhance the functionality of artificial tissues and joints in living organisms.
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Quasi‐Continuous Defect Levels in Broadband Gap: A New Strategy for High‐Temperature Long Persistent Luminescence Materials
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Long persistent luminescence (LPL) materials widely employed in the fields of emergency lighting and anti‐counterfeiting are mostly used at room temperature. As temperatures rise, the performance of LPL materials deteriorates dramatically, which hinders their application in in vivo imaging, high‐temperature display, and information storage. Herein, a multifunctional material LiGa5O8:Tb³⁺ (LGT) with green high‐temperature LPL (HT‐LPL) and blue cathodoluminescence (CL) is reported. Its LPL performance is anomalously enhanced with increasing temperature, and the duration time is more than 8 h at 423 K. With combined temperature‐dependent decay curves and thermoluminescence analyses, the unique quasi‐continuous defect levels are found in the band gap. The high‐concentration carriers in deep traps are frozen at room temperature and activated only at high temperatures, accompanied by changes in energy transfer pathways. The excellent HT‐LPL makes LGT a light‐emitting component of next‐generation smart wearable devices, as well as high‐temperature warning equipment in deep well exploration at a depth of 4500 m. The intense anti‐degradation blue CL makes it suitable for field emission displays, while the manipulable emission property makes it suitable for high‐level anti‐counterfeiting. This study fills a gap in HT‐LPL materials and opens up a new gateway for the efficient design of HT‐LPL and other multifunctional materials.
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Multi‐mode mechanoluminescence (ML) materials are have applications such as anti‐counterfeiting, stress sensing, and information security. There is limited general consensuses on the luminescent mechanisms, even though exploring ML mechanism based on defects has shown significance in further studies exploring both ML materials design and application. Here, a deep‐red to near‐infrared (NIR) ML material is reported in a Mn²⁺‐activated double perovskite‐type compound (CaZnGe2O6: Mn²⁺). The abundant lattice sites within the crystal structure have enabled Mn²⁺ doping and defects. Two different photoluminescence (PL) emission bands peaked at 536 and 676 nm from ⁴T1(⁴G)→⁶A1(⁶S) are observed, which are attributed to the substitution of Zn²⁺ and Ca²⁺ sites by Mn²⁺, respectively. Hence, tunable emissions from green to red are realized in single Mn²⁺ doping, which can be further regulated by varying the Mn²⁺ concentration. Electrons and holes are captured by cation and anion defects (VZn′′VZn′′V_{{\mathrm{Zn}}}^{\prime \prime } and VCa′′VCa′′V_{{\mathrm{Ca}}}^{\prime \prime }, VO••VO∙∙V_{\mathrm{O}}^{ \bullet \bullet }, vacancy of Zn, Ca and O ions), followed by the combination of such carriers to transfer energy to the Mn²⁺ 3d states to produce ML/persistent luminescence (PersL) under mechanical/thermal stimuli. Proof‐of‐concept applications in multi‐mode anti‐counterfeiting, temperature sensing, and X‐ray imaging fields are demonstrated. These results will deepen the understanding of single Mn²⁺‐doped multi‐stimulus‐responsive ML materials, inspiring the development of more high‐performance ML phosphors for practical applications.
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