Magnetoplasmonic Metasurface-Modulated Electrochemiluminescence Strategy for Extracellular Vesicle Detection.

Due to the ideal optical manipulation ability, the metasurface has broad prospects in the development of novel optical research. In particular, an active metasurface can control optical response through external stimulus, which has attracted great research interest. However, achieving effective modulation of the optical response is a significant challenge. In this work, we have developed a novel electrochemiluminescence (ECL) signal modulation strategy by an active magnetoplasmonic metasurface under an external magnetic field. The magnetoplasmonic metasurface was assembled based on yolk-shell Fe3O4@Au nanoparticles (Fe3O4@Au YS-NPs). On the one hand, the yolk-shell structure of Fe3O4@Au YS-NPs possessed the surface plasmon coupling effect and cavity-based Purcell effect, which provided high-intensity electromagnetic hot spots in the magnetoplasmonic metasurface. On the other hand, due to the strong magnetic response of the Fe3O4 core, the local magnetic field was induced by the external magnetic field, which further generated Lorentz force acting on the free electrons of Au nanoshells with strong optical anisotropy. The plasmon frequency of the metasurface can be effectively modulated by the Lorentz force effect. As a result, the ECL signal of nitrogen dots (N dots) was dynamically modulated and significantly enhanced at a specific polarization angle by the magnetoplasmonic metasurface under the variable external magnetic field. Based on the luminescence modulation ability and structure feature, the magnetoplasmonic metasurface was further established successfully as a sensing interface for gastric cancer (GC) extracellular vesicle (EV) detection. This study illustrated that the electromagnetic response of the active metasurface can effectively improve the optical modulation ability and luminescence sensing performance.

Hydrogen Sulfide Ameliorates Heart Aging by Downregulating Matrix Metalloproteinase-9.

PURPOSE: Aging contributes significantly to cardiovascular diseases and cardiac dysfunction, leading to the upregulation of matrix metalloproteinase-9 (MMP-9) in the heart and a significant decrease in hydrogen sulfide (H2S) content, coupled with impaired cardiac diastolic function. This study explores whether supplementing exogenous hydrogen sulfide during aging ameliorates the decline in H2S concentration in the heart, suppresses MMP-9 expression, and improves the age-associated impairment in cardiac morphology and function. METHODS: We collected plasma from healthy individuals of different ages to determine the relationship between aging and H2S and MMP-9 levels through Elisa detection and liquid chromatography-tandem mass spectrometry (LC/MC) detection of plasma H2S content. Three-month-old mice were selected as the young group, while 18-month-old mice were selected as the old group, and sodium hydrosulfide (NaHS) was injected intraperitoneally from 15 months old until 18 months old as the old + NaHS group. Plasma MMP-9 content was detected using Elisa, plasma H2S content, cardiac H2S content, and cystathionine gamma-lyase (CSE) activity were detected using LC/MC, and cardiac function was detected using echocardiography. Heart structure was assessed using hematoxylin and eosin staining, Masone staining was used to detect the degree of cardiac fibrosis, while western blot was used to detect the expression of MMP-9, CSE, and aging marker proteins. Knockdown of MMP-9 and CSE in H9c2 cells using small interfering RNA was carried out to determine the upstream-downstream relationship between MMP-9 and CSE. RESULTS: H2S content in the plasma of healthy individuals decreases with escalating age, whereas MMP-9 level rises with age progression. Aging leads to a decrease in H2S levels in the heart and plasma of mice, severe impairment of cardiac diastolic function, interstitial relaxation, and fibrosis of the heart. Supplementing with exogenous H2S can improve these phenomena. CONCLUSION: H2S maintains the structure and function of the heart by inhibiting the expression of MMP-9 during the aging process.

Bismuth Nano-Nest/Ti3CN Quantum Dot-Based Surface Plasmon Coupling Electrochemiluminescence Sensor for Ascites miRNA-421 Detection.

In this study, a novel surface plasmon-coupled electrochemiluminescence (SPC-ECL) biosensor was developed based on bismuth nano-nest and Ti3CN quantum dots (Ti3CN QDs). First, MXene derivative QDs (Ti3CN QDs) with excellent luminescence performance were prepared as the ECL luminescent. The N doping in Ti3CN QDs can effectively improve the luminescence performance and catalytic activity. Therefore, the luminescence performance of QDs has been effectively improved. Furthermore, the bismuth nano-nest structure with a strong localized surface plasmon resonance effect has been designed as the sensing interface via the electrochemical deposition method. It was worth noticed that the morphology of bismuth nanomaterials can be controlled effectively on the electrode surface by the step potential method. Due to the abundant surface plasmon hot spots generated between the bismuth nano-nests, the isotropic ECL signal of Ti3CN QDs can be not only significantly enhanced by 5.8 times but also converted into polarized emission. Finally, the bismuth nano-nest/Ti3CN QD-based SPC-ECL sensor was used to quantify miRNA-421 in the range of 1 fM to 10 nM. The biosensor has been successfully used for miRNA in ascites samples from gastric cancer patients, which indicated that the SPC-ECL sensor developed in this study has great potential for clinical analysis.

Asymmetric Heterodimer-Regulated Surface Plasmon Coupling ECL Polarization Strategy for MiRNA-182 Detection.

In this work, a novel plasmonic heterodimer with controllable hot spot was designed and applied to regulate surface plasmon coupling electrochemiluminescence (SPC-ECL) polarization sensing system. The heterodimer nanostructure consisted of individual Au-Ag core-shell nanocubes (Au@Ag NC) and Au nanospheres (Au NS), which were precisely assembled by thiol-DNA and biotin-streptavidin. The asymmetric nanostructure can significantly modulate the ECL intensity and emission polarization angle based on the synergy of the surface plasmon coupling (SPC) effect and the lightning rod effect with extraordinary field enhancement in the hot spot region. As a result, the isotropic ECL signal of zinc-doped nitrogen dots (Zn-N dots) was regulated in the directional emission. Furthermore, the SPC-ECL biosensor was successfully applied to detect miRNA-182 in triple-negative breast cancer (TNBC) tissues. The research on the established relationship between ECL polarization analysis and plasmonic heterodimers can provide a new pathway for the development of ECL sensing platforms.

Dynamically Metasurface-Modulated Electrochemiluminescence Polarization Coupling Angle Strategy for miR-142-3p Detection.

The combination of the electrochemiluminescence (ECL) technique with nanophotonics research can spark new analytical and sensing applications. Herein, we developed a novel modulation strategy of the ECL polarization angle based on the dynamically tunable few-layer metasurface. The bilayer metasurface consisted of a fixed Au-Ag core-shell nanocube array (Au@Ag NCA) layer with strong plasmonic hot spots and different amounts of the Au nanoparticles@MoS2 heterostructure nanosheet (0D-2D HNS) layer with strong metal-support interaction. Due to the interference and near-field coupling between layers, the bilayer metasurface can strongly redistribute the local electromagnetic field and energy in the ECL system, which not only significantly amplified the ECL signal but also modulated the polarization coupling angle. Therefore, the novel ECL polarization angle-resolved sensing strategy has been developed, which was beneficial to improve the sensitivity and resolution of ECL sensing. A dynamically tunable metasurface-based ECL biosensor was successfully used to detect the asthma-related miRNA-142-3p (miR-142-3p). Moreover, the simulation calculations of the electromagnetic field revealed the unique optical activity of the metasurface. This study brought the insightful understanding of the metasurface-modulated optical signal and provided a new idea to construct novel sensing platforms.

Hydrogen sulfide ameliorates endothelial dysfunction in aging arteries by regulating ferroptosis.

Aging causes vascular endothelial dysfunction. We aimed to investigate the causes of vascular endothelial dysfunction during aging using plasma and renal arteries from patients who underwent nephrectomy and animal models. The results showed that the endogenous H2S-producing enzyme cystathione-γ-lyase (CSE) protein expression was downregulated in renal artery tissue, plasma H2S levels were reduced. Moreover, elevated lipid peroxidation and iron accumulation levels led to ferroptosis and endothelial diastolic function in the renal arteries was impaired in the elderly group. H2S enhanced the endogenous CSE expression in the elderly group, promoted endogenous H2S production, decreased lipid peroxide expression, and inhibited ferroptosis, which in turn improved vascular endothelial function in the elderly group. In animal models, we also observed the same results. In addition, we applied NaHS, Ferrostatin-1 (ferroptosis inhibitor) and erastin (ferroptosis inducer) to incubate renal arteries of SD rats. The results showed that NaHS enhanced ferroptosis related proteins expression, inhibited ferroptosis and improved vascular endothelial function. We demonstrated that endothelial dysfunction associated with aging is closely related to reduced endogenous H2S levels and ferroptosis in vascular endothelial cells. Notably, H2S reduced lipid peroxidation levels in vascular endothelial cells, inhibited ferroptosis in vascular endothelial cells, and improved endothelial dysfunction.

Gold Nanorod Vertical Array-Based Electrochemiluminescence Polarization Assay for Triple-Negative Breast Cancer Detection.

In this work, a polarization-resolved electrochemiluminescence (ECL) sensor for microRNA-155 (miRNA-155) detection has been constructed based on the surface plasmon coupling effect. In the sensing system, nitrogen dots (N dots) were employed as ECL emitters. As a surface-enhanced structure, a gold nanorod vertical array was constructed on the electrode surface by the volatilization-induced self-assembly. The coupling of the adjacent gold nanorods in the array can generate significant local electromagnetic fields. Due to the anisotropy of gold nanorods and the hot spot effect of the vertical array, the ECL signal of N dots was greatly improved at a specific polarization angle. In addition, the catalytic hairpin self-assembly strategy was used to amplify the nucleic acid analyte signal. As a result, the polarization-resolved ECL sensor can detect miRNA-155 sensitively, which is related to triple-negative breast cancer.

Chemi-Mechanically Peeling the Unstable Surface States of α-FAPbI3.

Surface states are one of the crucial factors determining the phase stability of formamidinium-based perovskites. Compared with other compositions, exclusive lattice strain in FAPbI3 perovskite generates defects at the surface more readily, making them more vulnerable at the surface and easier to trigger the phase transition from α-phase to the non-perovskite δ-phase. In order to regulate the surface quality, here, a chemi-mechanical cleavage approach is reported, i.e., tape peel-zone (PZ), implemented by attaching and peeling off the ordinary Kapton Tapes. The PZ approach can simultaneously eliminate the surface defects of perovskite and siliconize the film surface with hydrophobic silicone compounds. These two functionalities endow α-FAPbI3 perovskite with a robust hydrophobic surface, which can sustain for 30 days under a relative humidity of 60% and withstand the high temperature up to 240 °C. The unencapsulated PZ-treated cells show 80.3% of initial performance after 90 h of continuous operation in ambient air, which is 31.4 times more stable than the pristine cell.

DNA-Mediated Au-Au Dimer-Based Surface Plasmon Coupling Electrochemiluminescence Sensor for BRCA1 Gene Detection.

Herein, we constructed a DNA-mediated Au-Au dimer-based surface plasmon coupling electrochemiluminescence (SPC-ECL) sensor. In the SPC-ECL sensing system, graphite phase carbon nitride quantum dots (GCN QDs) worked as an ECL emitter. A DNA rigid chain structure was employed to connect two Au NPs in an equilateral triangle configuration to form the Au-Au dimers. Due to the hot spot effect, the designed Au-Au dimers had a strong electromagnetic field intensity, which can greatly enhance the ECL signal of GCN QDs than a single Au nanoparticle. The gap distance of dimers can be effectively regulated by the DNA length, which resulted in different electromagnetic field intensities. Therefore, the different SPC-ECL amplification effects on the GCN QD signal by Au-Au dimers have been revealed. The maximum ECL signal of GCN QDs can be enhanced fourfold based on the Au-Au dimers with a gap distance of 2 nm. Furthermore, the biosensor showed good analytical performance for the detection of breast cancer susceptibility gene 1 (BRCA1 genes) (1 fM-1 nM) with a detection limit of 0.83 fM. This work provided an effective and precise SPC-ECL sensing mode for the diagnosis and prognosis of breast cancer.

MXene-Derived Quantum Dot@Gold Nanobones Heterostructure-Based Electrochemiluminescence Sensor for Triple-Negative Breast Cancer Diagnosis.

MXene material has been gradually studied in recent years due to its fascinating characteristics. This work developed a novel MXene-derived quantum dots (MQDs) @gold nanobones (Au NBs) heterostructure as the electrochemiluminescence (ECL) sensor. First, MXene and MQDs were synthesized via the green preparation process, which avoided the harm of hydrofluoric acid to humans and the environment. There was a strong ECL signal enhancement in the MQD@Au NBs heterostructure. On the one hand, Au NBs with surface plasmon resonance (SPR) effect acted as an "electronic regulator" that can transfer electrons to itself to control over-injection of electrons into the conduction band of MQDs. The luminous signal of MQDs can be efficiently generated and significantly amplified in the ECL sensing process. On the other hand, the work function of MQDs with excellent conductivity was relatively close to that of Au NBs in the heterostructure. So, ECL quenching caused by short-distance electron transfer between luminophore and Au nanomaterial has been effectively suppressed. The MQD@Au NBs heterostructure-based ECL sensing system was applied to determine miRNA-26a in the serum of patients with triple-negative breast cancer. It not only provides ideas for the green synthesis of MXene but also provides a guide for the application of MQD@Au NBs heterostructure in the field of ECL sensing.

Rational Fabrication of a Smart Electrochemiluminescent Sensor: Synergistic Effect of a Self-Luminous Faraday Cage and Biomimetic Magnetic Vesicles.

A smart electrochemiluminescent (ECL) sensor has been designed in this work. The sensing system consisted of Ag NPs-Ti3AlC2 nanosheets (Ag-TACS) as the self-luminous Faraday cage and biomimetic magnetic vesicles as the functional substrate. By engineering the structure and properties of Ti3AlC2 nanosheets to induce the Faraday-cage effect, the outer Helmholtz plane (OHP) was extended to contribute to ECL enhancement. Compared with the Faraday cage that further incorporated luminous materials, the self-luminous Faraday cage in the "direct label" model kept all the luminous materials on the OHP. Meanwhile, biomimetic magneticvesicles with highly efficient fluidity were used to improve the sensing efficiency and obtain a perfect Faraday-cage structure to enhance the ECL signals. The highest ECL enhancement (ca. 25 times) has been achieved by the synergistic effect of the Faraday cage and biomimetic magnetic vesicles. This sensing system was used to detect the wild-type K-ras gene in the colorectal tumor tissue. It provides not only an important guide for the novel ECL sensing concept but also a smart modulation system of the electromagnetic field.

Multiplex Electrochemiluminescence Polarization Assay Based on the Surface Plasmon Coupling Effect of Au NPs and Ag@Au NPs.

A novel multiplex electrochemiluminescence (ECL) polarization assay was developed to detect breast cancer-related genes BRCA1 and BRCA2 simultaneously based on the polarization characteristics of surface plasmon-coupled electrochemiluminescence (SPC-ECL). In this work, boron nitride quantum dots (BN QDs) were used as ECL emitters, and gold nanoparticles (Au NPs) and gold-coated silver nanoparticles (Ag@Au NPs) were employed as surface plasmon materials. The surface plasmon coupling resonance of different metal NPs not only enhanced the ECL intensity but also converted the isotropic emission into directional emission. This study revealed the relation between the structure of metal nanomaterials and SPC-ECL, and a high polarization-resolved sensing system was designed to detect multitarget DNA from 100 aM to 1 nM simultaneously. Polarization-based multiple ECL analysis has broad prospects in related cancer diagnosis and treatment evaluation.

Polarization-Resolved Electrochemiluminescence Sensor Based on the Surface Plasmon Coupling Effect of a Au Nanotriangle-Patterned Structure.

This work focused on the construction of a nanomaterial-patterned structure for high-resolved ECL signal modulation. Due to the surface coupling effect, the different shapes and distribution states of surface plasmonic nanomaterials not only affect the luminescence intensity enhancement but also decide the electrochemiluminescence (ECL) polarization characteristics. Herein, tin disulfide quantum dots were synthesized via a solvothermal method as ECL emitters. Compared with other nanostructures, Au nanotriangle (Au NT) displayed both the localized surface plasmon resonance electromagnetic enhancement effect and the tip amplification effect, which had significant hot spot regions at three sharp tips. Therefore, self-assembled Au NT-based patterned structures with high density and uniform hot spots were constructed as ideal surface plasmonic materials. More importantly, the distribution states of the hot spots affect the polarization characteristics of ECL, resulting in directional ECL emission at different angles. As a result, a polarization-resolved ECL biosensor was designed to detect miRNA 221. Moreover, this polarization-resolved biosensor achieved good quantitative detection in the linear range of 1 fM to 1 nM and showed satisfactory results in the analysis of the triple-negative breast cancer patients' serum.

Mitochondria-targeted accumulation of oxygen-irrelevant free radicals for enhanced synergistic low-temperature photothermal and thermodynamic therapy.

BACKGROUND: Although lower temperature (< 45 °C) photothermal therapy (LPTT) have attracted enormous attention in cancer therapy, the therapeutic effect is still unsatisfying when applying LPTT alone. Therefore, combining with other therapies is urgently needed to improve the therapeutic effect of LPTT. Recently reported oxygen-irrelevant free radicals based thermodynamic therapy (TDT) exhibit promising potential for hypoxic tumor treatment. However, overexpression of glutathione (GSH) in cancer cells would potently scavenge the free radicals before their arrival to the specific site and dramatically diminish the therapeutic efficacy. METHODS AND RESULTS: In this work, a core-shell nanoplatform with an appropriate size composed of arginine-glycine-aspartate (RGD) functioned polydopamine (PDA) as a shell and a triphenylphosphonium (TPP) modified hollow mesoporous manganese dioxide (H-mMnO2) as a core was designed and fabricated for the first time. This nanostructure endows a size-controllable hollow cavity mMnO2 and thickness-tunable PDA layers, which effectively prevented the pre-matured release of encapsulated azo initiator 2,2'-azobis[2-(2-imidazolin-2-yl) propane] dihydrochloride (AIBI) and revealed pH/NIR dual-responsive release performance. With the mitochondria-targeting ability of TPP, the smart nanocomposites (AIBI@H-mMnO2-TPP@PDA-RGD, AHTPR) could efficiently induce mitochondrial associated apoptosis in cancer cells at relatively low temperatures (< 45 °C) via selectively releasing oxygen-irrelevant free radicals in mitochondria and facilitating the depletion of intracellular GSH, exhibiting the advantages of mitochondria-targeted LPTT/TDT. More importantly, remarkable inhibition of tumor growth was observed in a subcutaneous xenograft model of osteosarcoma (OS) with negligible side effects. CONCLUSIONS: The synergistic therapy efficacy was confirmed by effectively inducing cancer cell death in vitro and completely eradicating the tumors in vivo. Additionally, the excellent biosafety and biocompatibility of the nanoplatforms were confirmed both in vitro and in vivo. Taken together, the current study provides a novel paradigm toward oxygen-independent free-radical-based cancer therapy, especially for the treatment of hypoxic solid tumors.

Amplification of oxidative stress with lycorine and gold-based nanocomposites for synergistic cascade cancer therapy.

BACKGROUND: Despite advances of surgery and neoadjuvant chemotherapy during the past few decades, the therapeutic efficacy of current therapeutic protocol for osteosarcoma (OS) is still seriously compromised by multi-drug resistance and severe side effects. Amplification of intracellular oxidative stress is considered as an effective strategy to induce cancer cell death. The purpose of this study was to develop a novel strategy that can amplify the intracellular oxidative stress for synergistic cascade cancer therapy. METHODS AND RESULTS: A novel nanocomposite, composed of folic acid (FA) modified mesoporous silica-coated gold nanostar (GNS@MSNs-FA) and traditional Chinese medicine lycorine (Ly), was rationally designed and developed. Under near-infrared (NIR) irradiation, the obtained GNS@MSNs-FA/Ly could promote a high level of ROS production via inducing mitochondrial dysfunction and potent endoplasmic reticulum (ER) stress. Moreover, glutathione (GSH) depletion during ER stress could reduce ROS scavenging and further enable efficient amplification of intracellular oxidative stress. Both in vitro and in vivo studies demonstrated that GNS@MSNs-FA/Ly coupled with NIR irradiation exhibited excellent antitumor efficacy without noticeable toxicity in MNNG/HOS tumor-bearing mice. CONCLUSION: All these results demonstrated that GNS@MSNs-FA/Ly coupled with NIR irradiation could dramatically amplify the intra-tumoral oxidative stress, exhibiting excellent antitumor ability without obvious systemic toxicity. Taken together, this promising strategy provides a new avenue for the effective cancer synergetic therapy and future clinical translation.

Polarized-Electrochemiluminescence Biosensor Based on Surface Plasmon Coupling Strategy and Fluorine-Doped BN Quantum Dots.

The first polarized-electrochemiluminescence (ECL) biosensor is reported in this work. Surface plasmon coupling ECL (SPC-ECL) strategy is developed for the amplified polarization light of fluorine-doped BN quantum dot (F-BN QD) emitters. The generation of polarized-ECL is attributed to the characteristic of polarization-angle-dependent SPC effect. A polarized sandwich-type biosensor based on F-BN QDs and Au nanoparticles (Au NPs) is established to detect the K-ras gene. The polarized-ECL sensor is more sensitive with lower detection limit than the isotropic ECL sensing system. The sensor can quantify the K-ras gene from 0.1 fM to 10 nM, with the detection limit as 0.03 fM. This work not only explores polarized SPC-ECL, but also offers a new analytical method for clinical diagnosis. The generation of polarized-ECL and the amplification strategy of the SPC effect opens a new path for ECL-resolved analyses.

Tunable plasmon-assisted electrochemiluminescence strategy for determination of the rapidly accelerated fibrosarcoma B-type (BRAF) gene using concave gold nanocubes.

A tunable plasmon-assisted electrochemiluminescence (ECL) strategy is reported using concave Au nanocubes (Au CBs) for rapidly accelerated fibrosarcoma B-type (BRAF) detection. Concave Au CBs exhibit a strong surface plasmon coupling (SPC) effect between its sharp apexes and edges. The high spectral overlap with graphite phase carbon nitride quantum dots (g-C3N4 QDs) is achieved by tuning surface plasmon absorption peak of the concave Au CBs. It maximizes the SPC effect and enhances the ECL signal of g-C3N4 QDs 3-fold. The SPC effect of Au CBs is twice as high as with Au NPs. We also employed a toehold-mediated strand displacement (TMSD) strategy for sensitive target recycling amplification. Under optimal conditions, this sensor can determine BRAF gene from 1 pM to 1 nM with a detection limit of 3.06 × 10-5 nM (S/N = 3) and RSD 3.67%. With the aid of the TMSD strategy and tunable plasmon-assisted ECL sensing mode, this sensor also exhibits good analytical performance in human serum with satisfactory recovery of 90.2~109%. The proposed strategy provides a promising method to effectively enhance spectral overlap and detect BRAF gene.

New intelligent multifunctional SiO2/VO2 composite films with enhanced infrared light regulation performance, solar modulation capability, and superhydrophobicity.

Highly transparent, energy-saving, and superhydrophobic nanostructured SiO2/VO2 composite films have been fabricated using a sol-gel method. These composite films are composed of an underlying infrared (IR)-regulating VO2 layer and a top protective layer that consists of SiO2 nanoparticles. Experimental results showed that the composite structure could enhance the IR light regulation performance, solar modulation capability, and hydrophobicity of the pristine VO2 layer. The transmittance of the composite films in visible region (Tlum) was higher than 60%, which was sufficient to meet the requirements of glass lighting. Compared with pristine VO2 films and tungsten-doped VO2 film, the near IR control capability of the composite films was enhanced by 13.9% and 22.1%, respectively, whereas their solar modulation capability was enhanced by 10.9% and 22.9%, respectively. The water contact angles of the SiO2/VO2 composite films were over 150°, indicating superhydrophobicity. The transparent superhydrophobic surface exhibited a high stability toward illumination as all the films retained their initial superhydrophobicity even after exposure to 365 nm light with an intensity of 160 mW . cm-2 for 10 h. In addition, the films possessed anti-oxidation and anti-acid properties. These characteristics are highly advantageous for intelligent windows or solar cell applications, given that they can provide surfaces with anti-fogging, rainproofing, and self-cleaning effects. Our technique offers a simple and low-cost solution to the development of stable and visible light transparent superhydrophobic surfaces for industrial applications.

The luminescent principle and sensing mechanism of metal-organic framework for bioanalysis and bioimaging.

Metal-organic frameworks (MOFs) porous material have obtained more and more attention during the past decade. Among various MOFs materials, luminescent MOFs with specific chemical characteristics and excellent optical properties have been regarded as promising candidates in the research of cancer biomarkers detection and bioimaging. Therefore, the latest advances and the principal biosensing and imaging strategies based on the luminescent MOFs were discussed in this review. The effective synthesis methods of luminescent MOFs were emphasized firstly. Subsequently, the luminescent principle of MOFs has been summarized. Furthermore, the luminescent MOF-based sensing mechanisms have been highlighted to provide insights into the design of biosensors. The designability of LMOFs was suitable for different needs of biorecognition, detection, and imaging. Typical examples of luminescent MOF in the various cancer biomarkers detection and bioimaging were emphatically introduced. Finally, the future outlooks and challenges of luminescent MOF-based biosensing systems were proposed for clinical cancer diagnosis.

The ECL enhancement of MBene QDs with nanoparticle-on-mirror structure for sensitive detection of exosomal miRNA.

Thyroid cancer is the most prevalent endocrine malignancy. The development of sensitive and reliable methods to detect the thyroid cancer is the currently urgent requirement. Herein, we developed an electrochemiluminescence (ECL) biosensor based on MBene derivative quantum dots (MoB QDs) and Ag NP-on-mirror (NPoM) nanocavity structure. On the one hand, MBene QDs as a novel luminescent material in the ECL process was reported for the first time, which can react with H2O2 as co-reactant. On the other hand, the NPoM nanostructure was successfully constructed with the Ag mirror and Ag NPs to provide highly localized hot spots. The NPoM structure had high degree of light field confinement and electromagnetic field enhancement, which can amplify the ECL signal as the signal modulator. Therefore, the synergistic effect of the nanocavity and localized surface plasmon resonance (LSPR) mode in the NPoM facilitated the enhancement of the ECL signal of MoB QDs over 21.7 times. Subsequently, the proposed ECL biosensing system was employed to analyze the expression level of miRNA-222-3p in the thyroid cancer exosome. The results indicated the relative association between miRNA-222-3p and BRAFV600E mutation. The MoB QDs/NPoM biosensor displayed the ideal potential in assessing thyroid cancer progression for advancing clinical diagnosis applications.