DNA Gate-Based CRISPR-Cas Exponential Amplification System for Ultrasensitive Small Extracellular Vesicle Detection to Enhance Breast Cancer Diagnosis.

Tumor-derived small extracellular vesicles (tEVs) as potential biomarkers possess abundant surface proteins closely related to parent cells, which are crucial for noninvasive cancer diagnosis. However, tEVs exhibit phenotype heterogeneity and low abundance, posing a significant challenge for multiplex detection with a high sensitivity. Herein, we developed a DNA gate-based exponential amplification CRISPR-Cas (DGEAC) system for accurate and ultrasensitive detection of tEVs, which can greatly improve the accuracy of breast cancer (BC) diagnosis. Based on the coexpression of CD63 and vascular endothelial growth factor (VEGF) on BC-derived tEVs, we developed a dual-aptamer-based AND gate fluorescent probe by proximity hybridization. By integrating the target recognition and trans-cleavage activity of Cas12a, an autocatalysis-driven exponential amplification circuit was developed for ultrasensitive detection of CD63 and VEGF proteins on tEVs, which could avoid false negative signals from single protein or other interfering proteins. We achieved highly sensitive detection of tEVs over a linear range from 1.75 × 103 to 3.5 × 108 particles/mL with a detection limit as low as 1.02 × 103 particles/mL. Furthermore, the DGEAC system can distinguish tEVs from tEVs derived from different BC cell lines, including MDA-MB-231, MCF-7, SKBR3, and MCF-10A. Compared to linear amplification (AUC 90.0%), the DGEAC system effectively differentiates BC in different stages (AUC 98.3%).

Polymerase-Driven Logic Signal Amplification for the Detection of Small Extracellular Vesicle Surface Proteins and the Identification of Breast Cancer.

Small extracellular vesicles (sEVs) derived from tumors contain a vast amount of cellular information and are regarded as a potential diagnostic biomarker for noninvasive cancer diagnosis. Nevertheless, it remains challenging to accurately measure sEVs from clinical samples due to the low abundance of these vesicles as well as their phenotypic heterogeneity. Herein, a polymerase-driven logic signal amplification system (PLSAS) was developed for the high-sensitivity detection of sEV surface proteins and breast cancer (BC) identification. Aptamers were introduced to serve as sensing modules to specifically recognize target proteins. By changing the input DNA sequences, two polymerase-driven primer exchange reaction systems were rationally designed for DNA logic computing. This allows for autonomous targeting of a limited number of targets using "OR" and "AND" logic, leading to a significant increase in fluorescence signals and enabling the specific and ultrasensitive detection of sEV surface proteins. In this work, we investigated surface proteins of mucin 1 (MUC1) and the epithelial cell adhesion molecule (EpCAM) as model proteins. When MUC1 or EpCAM proteins were used as single signal input in the "OR" DNA logic system, the detection limit of sEVs was 24 or 58 particles/µL, respectively. And MUC1 and EpCAM proteins of sEVs can be simultaneously detected in the AND logic method, which can significantly reduce the effect of phenotypic heterogeneity of sEVs to distinguish the source of sEVs derived from various mammary cell lines, such as MCF-7, MDA MB 231, SKBR3, and MCF-10A. The approach has achieved high discrimination in serologically tested positive BC samples (AUC 98.1%) and holds significant potential in advancing the early diagnosis and prognostic assessments of BC.

Nucleic acid and nanomaterial-assisted signal-amplified strategies in fluorescent analysis of circulating tumor cells and small extracellular vesicles.

As two main types of liquid biopsy markers, both circulating tumor cells (CTCs) and small extracellular vesicles (sEVs) play important roles in the diagnosis and prognosis of cancers. CTCs are malignant cells that detach from the original tumor tissue and enter the circulation of body fluids. sEVs are nanoscale vesicles secreted by normal cells or pathological cells. However, CTCs and sEVs in body fluids are scarce, leading to great difficulties in the accurate analysis of related diseases. For the sensitive detection of CTCs and sEVs in body fluids, various types of nucleic acid and nanomaterial-assisted signal amplification strategies have been developed. In this review, we summarize the recent advances in fluorescent detection of CTCs and sEVs in liquid biopsy based on nucleic acid and nanomaterial-assisted signal amplification strategies. We also discuss their advantages, challenges, and future prospects.

Ratiometrically pH-Insensitive Upconversion Nanoprobe: Toward Simultaneously Quantifying Organellar Calcium and Chloride and Understanding the Interaction of the Two Ions in Lysosome Function.

Calcium and chloride levels are closely related to lysosome dysfunction. However, the simultaneous measurement of calcium (Ca2+) and chloride (Cl-) in acidic subcellular organelles, which is conducive to a deep understanding of lysosome-related biological events, remains a challenge. In this study, we developed a pH-insensitive, ratiometric NIR nanoprobe for the simultaneous detection of Ca2+ and Cl- in acidic lysosomes and determined the roles of the two ions in lysosome function. The upconversion nanoprobe with blue, green, and red emissions was modified with a Ca2+-sensitive dye (Rhod-5N) and Cl--responsive fluorophore (10,10'-bis[3-carboxypropyl]-9,9'-biacridinium dinitrate, BAC). As a result of a dual-luminescence resonance energy transfer between upconversion nanoparticles (UCNPs) and Rhod-5N/BAC, the blue and green upconversion luminescence (UCL) of UCNPs were quenched and the red UCL was used as the reference signal. The ratiometric upconversion nanoprobe possesses a specific ability for the concurrent recognition of Ca2+ and Cl- ions independent of the influence of the environmental pH. To locate the probe in the lysosome, dextran was further modified with upconversion nanoparticles. Then, the nanoprobe with a high spatial resolution was constructed for the simultaneous monitoring of Ca2+ and Cl- in acidic lysosomes. Moreover, it was found that the reduction of lysosomal Cl- affects the release of lysosomal Ca2+, which further blocks the activities of specific lysosomal enzymes. The ratiometric NIR nanoprobe has great potential for decoding and evaluating lysosomal diseases.

Cell-Membrane-Anchored Upconversion Nanoprobe for Near-Infrared Light Triggered Cell-Cell Interactions.

Manipulating cell-cell interactions is of great significance in cell communication and cell-based therapies. Although efforts have been made to construct cell-cell assembly by stimuli-responsive host-guest interactions, controllable cell-cell interactions by near-infrared (NIR) light triggered reversible assembly remain a challenge. Herein, we develop a NIR-controlled system based on ß-cyclodextrin (ß-CD) modified upconversion nanoparticles (UCNPs) for reversible and noninvasive manipulation of cell assembly and disassembly, which is realized by host-guest interactions between E/Z-photoisomerization of arylazopyrazole (AAP) and ß-CD under the NIR irradiation. UCNPs can convert NIR to ultraviolet light, which leads to the transformation of AAP from the E-isomer to the Z-isomer. And it can be reverted back to the E-isomer under visible light irradiation. This reversible photoisomerization can modulate the host-guest interaction between ß-CD and AAP, thus leading to reversible cell assembly and disassembly. Furthermore, by precise regulating cell-cell interactions by NIR light, cell-cell communication and molecular transportation can be realized. Given the diversity of host and guest molecules and the advantages of NIR light in biological applications, reversible cell-cell assembly has great potential for the regulation of cell behaviors and cell-based therapies.

An Ultrasensitive Strand Displacement Signal Amplification-Assisted Synchronous Fluorescence Assay for Surface Proteins of Small Extracellular Vesicle Analysis and Cancer Identification.

Small extracellular vesicles (sEVs), often known as exosomes, are expected to be a promising biomarker for the early diagnosis of cancer because they carry enriched proteins that originated from parent cells. Profiling surface proteins of sEVs offers non-invasive access for the early diagnosis of cancer. However, it remains challenging to simultaneously detect surface proteins of sEVs with desired sensitivity. Herein, a dual color DNA nanodevice based on toehold-mediated DNA strand displacement signal amplification and the synchronous fluorescence technique has been developed for simultaneous analysis of surface proteins of sEVs with high sensitivity. As for the DNA nanodevice-based system, the nanoconjugates of aptamer-magnetic beads can recognize surface proteins of sEVs and lead to the release of single-stranded DNA. Then, the released DNA can trigger toehold-mediated DNA strand displacement for signal amplification. In this system, a CD63 aptamer and MUC1 aptamer were used as recognition elements for the detection of surface proteins of sEVs isolated from cancer cells. Under the optimal conditions, the corresponding proteins of sEVs were simultaneously determined with ultrasensitivity by the synchronous fluorescence method. Also, the detection limits of sEVs by two surface proteins were 67 particles/µL by CD63 and 37 particles/µL by MUC1. Of note, the as-constructed method can be applied to recognize sEVs from different tumor cell lines (SGC7901, HepG2, and MCF-7 cells). Furthermore, the system has been successfully applied to precisely identify cancer patients from healthy people by serum analysis. The strategy demonstrates great potential applications in the early diagnosis of cancer.

Dual-Channel Fluorescent Probe for the Detection of Peroxynitrite and Glutathione in Mitochondria: Accurate Discrimination of Inflammatory and Progressing Tumor Cells.

Distinguishing between normal, inflammatory, and progressing tumor cells plays a vital role in early diagnoses and clinical studies. The simultaneous quantification of multiple biomarkers in cells can reveal cellular heterogeneity, which contributes to the discrimination of different types of cells. Herein, a dual-channel fluorescent probe has been developed for monitoring peroxynitrite (ONOO-) and glutathione (GSH) to accurately discriminate normal cells, inflammatory cells, and progressing cancer cells. The probe can monitor exogenous and endogenous mitochondrial GSH and ONOO- in living cells and zebrafish by green (530 nm, G530) and red (630 nm, R630) emission based on its good selectivity and low biotoxicity. GSH and ONOO- are visualized via fluorescence imaging, and the corresponding output signals can be employed to differentiate nontumorigenic, malignant, and metastatic breast cells in cocultured cells. Furthermore, the accurate discrimination among normal, inflammatory, and cancerous cells is achieved through the changes in the dual-channel fluorescence signal, which shows great potential for the diagnosis of inflammation and cancer diseases.

Ultrasensitive detection of tumor-derived small extracellular vesicles based on nonlinear hybridization chain reaction fluorescence signal amplification and immunomagnetic separation.

Small extracellular vesicles (sEVs) have attracted wide attention as a promising tumor biomarker. However, sensitive and selective detection of sEVs is challenging due to the low levels of sEVs in the early stage of cancers. Herein, a novel fluorescent sensor was developed for the detection of sEVs with high sensitivity and selectivity based on nonlinear hybridization chain reaction (nHCR) signal amplification and immunomagnetic separation. Firstly, sEVs were captured and enriched by CD63 antibody conjugated magnetic beads via antibody-antigen reactions. Then, cholesterol-modified DNA probes were anchored spontaneously on lipid membranes of sEVs through efficient hydrophobic interactions between the cholesterol moiety and the phospholipid bilayer of sEVs. The simultaneous recognition of the transmembrane protein and the phospholipid bilayer structure of the sEVs could effectively eliminate interferences from free proteins. The sticky ends of the cholesterol-modified DNA probes acted as the initiator to trigger nHCR to form a hyperbranched network of DNA structure that could recruit more fluorescent signal molecules for signal amplification. Under the optimal conditions, the nHCR-based strategy showed high sensitivity for the detection of sEVs with a limit of detection of 80 particles per µL. In addition, the as-constructed method was successfully applied for the analysis of clinical samples. It provides a sensitive and selective platform for the isolation and detection of sEVs in the early diagnosis of cancers.

Iron-doped cerium/nucleotide coordination polymer as highly efficient peroxidase mimic for colorimetric detection of fluoride ion.

A new coordination polymer (Ce-Fe-GMP) with excellent catalytic activity was prepared by a facile route, which was further applied to the detection of F- with high sensitivity and selectivity. The simple doping of Fe3+ into the coordination network can easily modulate the mixing ratio of Ce3+ and Ce4+ in the presence of H2O2, which can extremely improve the catalytic ability of Ce-Fe-GMP. Based on the synergistic effect, the Ce-Fe-GMP with dual-active sites shows better peroxidase activity than that of Ce-GMP. In addition, we found that F- can inhibit the peroxidase activity of Ce-Fe-GMP because of the coordination structure fragmentation and the regulation of Ce3+/Ce4+ ratio. Therefore, different concentrations of F- can be detected by the colorimetric reaction based on this mechanism. The absorption at 652 nm displays a good linear relationship versus the concentration of F- over the range 2.0 to 100.0 µM. Furthermore, F- in real mineral-mixed samples can be measured with satisfactory results. The colorimetric strategy based on the peroxidase activity of Ce-Fe-GMP is simple and low-cost, which shows the potential applications in the field of on-site environment measurement.

Rational Modulation of the Luminescence of Upconversion Nanomaterials with Phycocyanin for the Sensing and Imaging of Myeloperoxidase during an Inflammatory Process.

Myeloperoxidase (MPO) is a heme peroxidases protein associated with many inflammation-related diseases. Although many fluorescent probes have been constructed for the assessment of MPO activity, it still remains a challege to develop a nanoprobe for highly sensitive biosensing and high-resolution bioimaging in biological system. In this work, we developed a novel luminescent nanoprobe based on upconversion nanoparticles (UCNPs) conjugated with phycocyanin (PC), which could detect the fluctuation of MPO. By grafting PC onto the surface of UCNPs through amidation reaction, the luminescence of UCNPs is quenched by PC via energy transfer. Due to the specific recognition by PC, the nanoprobe can be used for sensitive evaluation the bioactivity of MPO. The nanoprobe based on PC-UCNPs has been successfully applied for the bioimaging of MPO in living cells and an inflammatory process by taking an acute liver injury mouse as a model.

Near-Infrared Light-Switched MoS2 Nanoflakes@Gelatin Bioplatform for Capture, Detection, and Nondestructive Release of Circulating Tumor Cells.

The integrative bioplatform for capture, detection and release of circulating tumor cells (CTCs) is of great significance in clinical diagnosis and biomedical research. To fulfill this demand, we introduced a near-infrared (NIR) light-switched bioplatform for efficient isolation and downstream analysis of CTCs. The platform was created by first modifying the PEG-MoS2 nanoflakes (NFs)@gelatin nanocomposite on the ITO surface, and then introducing the MUC1 aptamer as a specific recognition element via coupling reaction between aptamer and gelatin to achieve the specific capture for CTCs. Subsequently, the captured cells are released under a NIR light irradiation (808 nm) by using MoS2 NFs as the NIR-regulated control element. Significantly, this platform could capture and release of CTCs with an excellent capture/release efficiency of 89.5% and 92.5%, respectively. Furthermore, the electrochemical bioplatform exhibited a wide linear range for the detection of CTCs from 50 to 1 × 106 cells mL-1 with a detection limit of 15 cells mL-1. After 5 days of reculture, the released cells still maintain good cell shape and proliferation capacity. Moreover, the bioplatfrom is a simple, versatile, and universal system for the recognition, capture, release, and detection of different types of CTCs. Therefore, this bioplatform shows potential applications on the early diagnosis of cancers.

Ratiometric Upconversion Luminescence Nanoprobe with Near-Infrared Ag2S Nanodots as the Energy Acceptor for Sensing and Imaging of pH in Vivo.

A luminescence resonance energy transfer (LRET) system was successfully developed using near-infrared (NIR) Ag2S nanodots (NDs) as the energy acceptors and upconversion nanoparticles (UCNPs) as the energy donors. The system possessing the properties of NIR excitation (980 nm) and NIR emission (795 nm) was used for the ratiometric detection and bioimaging of pH in tumor cells and zebrafish. Glutathione and mercaptopropionic acid (MPA) co-modified Ag2S NDs (GM-Ag2S NDs) were prepared by ligand exchange with an excellent pH-responsive property over a pH range of 4.0 to 9.0. The NIR GM-Ag2S NDs were covalently grafted with silica coated UCNPs, and an efficient LRET platform was developed via modulation of the thickness of the silica coating. Due to the LRET process between UCNPs and GM-Ag2S NDs, a ratiometric luminescence nanoprobe with the properties of NIR excitation-NIR emission was constructed for pH biosensing and bioimaging. On the basis of high contrast bioimaging, the nanoplatform can distinguish between tumor and normal tissue in the zebrafish model.

Near-Infrared Fluorescent Ag2S Nanodot-Based Signal Amplification for Efficient Detection of Circulating Tumor Cells.

The level of circulating tumor cells (CTCs) plays a critical role in tumor metastasis and personalized therapy, but it is challenging for highly efficient capture and detection of CTCs because of the extremely low concentration in peripheral blood. Herein, we report near-infrared fluorescent Ag2S nanodot-based signal amplification combing with immune-magnetic spheres (IMNs) for highly efficient magnetic capture and ultrasensitive fluorescence labeling of CTCs. The near-infrared fluorescent Ag2S nanoprobe has been successfully constructed through hybridization chain reactions using aptamer-modified Ag2S nanodots, which can extremely improve the imaging sensitivity and reduce background signal of blood samples. Moreover, the antiepithelial-cell-adhesion-molecule (EpCAM) antibody-labeled magnetic nanospheres have been used for highly capture rare tumor cells in whole blood. The near-infrared nanoprobe with signal amplification and IMNs platform exhibits excellent performance in efficient capture and detection of CTCs, which shows great potential in cancer diagnostics and therapeutics.

Polydopamine nanodots are viable probes for fluorometric determination of the activity of alkaline phosphatase via the in situ regulation of a redox reaction triggered by the enzyme.

The authors describe an environmentally friendly and fast (~14 min) method for the synthesis of homogeneously distributed fluorescent polydopamine nanodots (PDA-NDs) using KMnO4 as the oxidant. Alkaline phosphatase (ALP) catalyzes the hydrolysis of ascorbic acid 2-phosphate to release free ascorbic acid which undergoes an in-situ redox reaction with KMnO4. Depending on the activity of ALP, more or less KMnO4 is consumed, and this affects the formation of the PDA-NDs. Based on this finding, a sensitive method was worked out to quantify the activity of ALP via real-time formation of fluorescent PDA-NDs. The fluorometric signal (best measured at excitation/emission peaks of 390/500 nm) is linear in the 1 to 50 mU·mL-1 ALP activity range, and the limit of the detection is as low as 0.94 mU·mL-1 (based on 3 σ/m). The method was successfully applied to the determination of ALP activity in spiked human serum and in MCF-7 cell lysates. It was also applied in a method to screen for inhibitors of ALP. Graphical abstract Schematic of a fluorometric method for the determination of alkaline phosphatase (ALP) activity. The method is based on the in-situ regulation of the formation of fluorescent polydopamine nanodots (PDA-NDs) through the competition between the KMnO4-induced polymerization of dopamine and ALP-directed ascorbic acid 2-phosphate (Asc-2P) hydrolysis. AA: Ascorbic acid.

Construction of a Graphene/Au-Nanoparticles/Cucurbit[7]uril-Based Sensor for Pb(2+) Sensing.

The development of highly sensitive and selective methods for the detection of lead ion (Pb(2+)) is of great scientific importance. In this work, we develop a new surface-enhanced Raman scattering (SERS)-based sensor for the selective trace measurement of Pb(2+). The SERS-based sensor is assembled from gold nanoparticles (AuNPs) and graphene using cucurbit[7]uril (CB[7]) as a precise molecular glue and a local SERS reporter. Upon the addition of Pb(2+), CB[7] forms stronger complexes with Pb(2+) and desorbs from AuNPs, resulting in a sensitive "turn-off" of SERS signals. This SERS-based assay shows a limit of detection (LOD) of 0.3 nm and a linear detection range from 1 nm to 0.3 µm for Pb(2+). The feasibility of the assay is further demonstrated by probing Pb(2+) in real water samples. This SERS-based analytical method is highly sensitive and selective, and therefore holds promising applications in environmental analysis.

Graphene based electrochemical biosensor for label-free measurement of the activity and inhibition of protein tyrosine kinase.

In this paper, we report a simple, ultrasensitive and label-free method to evaluate the activity of protein tyrosine (Tyr) kinase based on the electrochemical signal of Tyr residues at a graphene modified glassy carbon electrode. It was found that graphene could enhance the electrochemical response of Tyr through electrocatalytic oxidation reaction. After phosphorylation by kinase, the phosphorylated Tyr (pTyr) is electro-inactive and the electrochemical signal is reduced. Therefore, the electrochemical response of Tyr residues in peptides can be used as a signal reporter to assay kinase activity. In this study, using Src-catalyzed Tyr-phosphorylation as a model, the activity of kinase can be evaluated with a linear range from 0.26 to 33.79 nM and an extraordinarily low detection limit of 0.087 nM. Moreover, this electrochemical biosensor can also be utilized for monitoring the inhibition of kinase using 4-amino-5-(4-chlorophenyl)-7-(tert-butyl) pyrazolo [3,4-d] pyrimidine, a small molecule inhibitor. On the basis of the inhibitor concentration dependent Tyr oxidation signal, the IC50 value was estimated to be 99 nM.

Endogenous stimulus-controlled estradiol@AIEgen-based covalent organic framework for reduction of myocardial ischemia/reperfusion injury.

ATP stimulus-responsive tetrahedral DNA-gated fluorescent covalent organic frameworks (COFs) were developed for estradiol (E2) delivery and controllable release. The fluorescent COFs with an efficient E2 loading showed great potential against myocardial ischemia and reperfusion injury.

A near-infrared light-activated nanoprobe for simultaneous detection of hydrogen polysulfide and sulfur dioxide in myocardial ischemia-reperfusion injury.

Ischemia-reperfusion-induced cardiomyocyte mortality constitutes a prominent contributor to global morbidity and mortality. However, early diagnosis and preventive treatment of cardiac I/R injury remains a challenge. Given the close relationship between ferroptosis and I/R injury, monitoring their pathological processes holds promise for advancing early diagnosis and treatment of the disease. Herein, we report a near-infrared (NIR) light-activated dual-responsive nanoprobe (UCNP@mSiO2@SP-NP-NAP) for controllable detection of hydrogen polysulfide (H2Sn) and sulfur dioxide (SO2) during ferroptosis-related myocardial I/R injury. The nanoprobe's responsive sites could be activated by NIR and Vis light modulation, reversibly alternating for at least 5 cycles. We employed the nanoprobe to monitor the fluctuation levels of H2Sn and SO2 in H9C2 cardiomyocytes and mice, revealing that H2Sn and SO2 levels were up-regulated during I/R. The NIR light-activated dual-responsive nanoprobe could be a powerful tool for myocardial I/R injury diagnosis. Moreover, we also found that inhibiting the initiation of the ferroptosis process contributed to attenuating cardiac I/R injury, which indicated great potential for treating I/R injury.

An erythrocyte membrane-camouflaged fluorescent covalent organic framework for starving/nitric oxide/immunotherapy of triple-negative breast cancer.

It is a great challenge to effectively treat triple-negative breast cancer (TNBC) due to lack of therapeutic targets and drug resistance of systemic chemotherapy. Rational design of nanomedicine with good hemocompatibility is urgently desirable for combination therapy of TNBC. Herein, an erythrocyte membrane-camouflaged fluorescent covalent organic framework (COF) loaded with an NO donor (hydroxyurea, Hu), glucose oxidase (GOx) and cytosine-phosphate-guanine oligonucleotides (CPG) (COF@HGC) was developed for imaging-guided starving/nitric oxide (NO)/immunization synergistic treatment of TNBC. The substances of HGC are easily co-loaded onto the COF due to the ordered pore structure and large surface area. And a folic acid-modified erythrocyte membrane (FEM) is coated on the surface of COF@HGC to improve targeted therapy and haemocompatibility. When COF@HGC@FEM is internalized into tumor cells, hemoglobin (Hb) on FEM and GOx loaded on the COF can trigger cascade reactions to kill tumor cells due to the simultaneous production of NO and exhaustion of glucose. Meanwhile, the COF with excellent fluorescence properties can be used as a self-reporter for bioimaging. Furthermore, the CPG can reprogram tumor-associated macrophages from tumor-supportive phenotype to anti-tumor phenotype and enhance immunotherapy. Through the "three-in-one" strategy, the biomimetic nanoplatform can effectively inhibit tumor growth and reprogram the tumor immunosuppression microenvironment in the TNBC mouse model.

Dye-sensitized rare-earth-doped nanoprobe for simultaneously enhanced NIR-II imaging and precise treatment of bacterial infection.

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for causing life-threatening infections that result in high morbidity and mortality rates. The development of advanced imaging and therapeutic methods for in vivo diagnosis and treatment of MRSA infections remains challenging. Here, we develop a hybrid nanoplatform based on rare-earth-doped nanoparticles (RENPs) sensitized by a moiety-engineered near-infrared (NIR) TPEO-820 dye and with a ZIF-8 layer that incorporates CysNO, a photochemically triggered nitric oxide donor. We then use the hybrid for both NIR-II bioimaging and photoactivatable treatment of MRSA-infected wounds. We show that the NIR dye sensitization leads to an 8.5-fold enhancement of the downshifting emission and facilitates deep-tissue NIR-II imaging of bacterial infections. Moreover, the sensitization strategy enhances the UV emission of RENPs by two orders of magnitude, leading to the efficiently controllable release of nitric oxide for effective disinfection of MRSA in vitro and in vivo. The hybrid nanoplatform thus offers promising opportunities for simultaneous localization and controllable treatment of MRSA. STATEMENT OF SIGNIFICANCE: Early detection and treatment of MRSA infections are crucial for reducing public health risks. It is a significant challenge that develops sensitive in vivo diagnosis and complete elimination of drug-resistant bacterial infections. Herein, a nanoplatform has been developed for photoactivatable therapy of MRSA infections and deep tissue NIR-II imaging. This platform utilizes lanthanide-doped rare earth nanoparticles (RENPs) that are sensitized by a moiety-engineered near-infrared (NIR) dye TPEO-820. The TPEO-820 sensitized RENPs exhibit 5 times increase in the release of NO concentration for MRSA treatment compared to unsensitized RENPs, enabling precise therapy of MRSA infection both in vitro and in vivo. Moreover, the platform demonstrates NIR-II luminescence in vivo, allowing for sensitive imaging in deep tissue for MRSA infection.