Microextraction techniques with deep eutectic solvents for gas chromatographic analysis: a minireview.

Sample pretreatment is one of the key steps in sample analysis. The design and development of new materials promote advancements in sample pretreatment technology. Deep eutectic solvents (DESs) are a novel material that have been developed in recent years. They possess characteristics such as low toxicity, good thermal stability, simple preparation methods, and low cost. DESs have the potential to replace traditional organic extraction solvents. DESs are formed from a hydrogen bond donor (HBD) and acceptor (HBA). Changing the type of HBA and HBD or their ratio leads to variations in the structure and properties of the resulting DESs. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) are the primary analytical techniques used in laboratories. This paper analyzes the selection relationship between DESs and analytes, as well as the steps of sample pretreatment, based on the characteristics of GC instruments, and utilizing DES extractants and extraction materials for sample pretreatment. This paper summarizes the progress of DES-based microextraction methods for GC. It introduces the different classifications of liquid and solid-phase microextraction and the application of DESs in them. The theoretical mechanism and extraction/separation mechanism of DESs are analyzed, and potential application of DESs in extraction/separation technology is discussed.

A turn-on anthraquinone-derived colorimetric and fluorometric dual-mode probe for highly selective Hg2+ determination and bioimaging in living organisms.

Mercury ion (Hg2+) is considered a harmful neurotoxin, and real-time monitoring of Hg2+ concentrations in environmental and biological samples is critical. Fluorescent probes are a rapidly emerging visualization tool owing to their simple design and good selectivity. Herein, a novel fluorescence (FL) probe 2-(4-((6-((quinolin-8-yloxy)methyl)pyridin-2-yl)methyl)piperazin-1-yl)anthracene-9,10-dione (QPPA) is designed using piperazine as a linker between the anthraquinone group, which serves as a fluorophore, and N4O as the Hg2+ ligand. The probe exhibits FL "turn-on" sensing of Hg2+ because the complex inhibits the photo-induced electron transfer (PET) process. Moreover, QPPA can overcome the invasion by other possible cations, resulting in a clear color change from orange to colorless with the addition Hg2+. The chelation of QPPA with Hg2+ in a 1:1 ratio. Subsequently, the theoretically determined binding sites of the ligand to Hg2+ are validated through 1H NMR titration. The in situQPPA-Hg2+ complex can be subjected to Hg2+ extraction following the introduction of S2- owing to its robust binding capacity. The exceptional limit of detection values for Hg2+ and S2- are obtained as 63.0 and 79.1 nM (S/N = 3), respectively. Moreover, QPPA can display bright red FL in the presence of Hg2+ in different biological specimens such as HeLa cells, zebrafish, onion root tip tissues, and water flea Daphnia carinata, further providing an effective strategy for environmental monitoring and bioimaging of Hg2+ in living organisms.

Observation of polarity changes in Sjogren's syndrome mice using a targeting lysosomes and ratiometric fluorescent probe.

Utilizing non-invasive, real-time dynamic imaging and high-resolution detection tools to track polarity changes in Sjögren's syndrome (SS) contributes to a better understanding of the disease progression. Herein, a ratiometric polarity-sensitive fluorescent probe (DIM) was designed and synthesized, DIM consisted of dicyanoisophorone as the fluorophore and morpholine moiety as lysosome targeting. DIM showed a ratiometric response to polarity and high selectivity (unaffected by viscosity, pH, ROS, RNS, etc.), offering a more accurate analysis of intracellular polarity through a built-in internal reference calibration. The polarity abnormality of submandibular glands in non-obese diabetic (NOD) mice was revealed and verified by in vivo ratiometric fluorescence imaging of DIM, suggesting that fluorescent probe have great potential in the diagnosis of salivary gland abnormalities.

Long-term tracking of lysosomal dynamics with highly stable fluorescent probe.

Monitoring lysosomal dynamics in real-time, especially in vivo, poses significant challenges due to the complex and dynamic nature of cellular environments. It is extremely important to construct fluorescent probes with high stability for imaging lysosomes to minimize interference from other cellular components, in order to ensure prolonged imaging. A fluorescent probe (PDB) has been proposed for targeting lysosomes, which was less affected to changes in the cellular microenvironment (such as pH, viscosity and polarity). PDB can be easily prepared by 4'-piperazinoacetophenone and 2-(4-diethylamino)-2-hydroxybenzoyl) benzoicacid, containing a piperazine group for labeling and imaging lysosomes and the high pKa value (∼9.35) allowed PDB to efficiently track lysosomes. The emission wavelength of PDB in aqueous solution was 634 nm (λex = 572 nm, Фf = 0.11). The dynamic process of lysosome induced by starvation and rapamycin was successfully explored by fluorescence imaging. Compared with the commercially available Lyso-Tracker green, the high photostability fluorescent probe can ensure 3D high-fidelity tracking and resist photobleaching. Therefore, PDB, unaffected by the cell microenvironment, successfully achieved long-term tracking of lysosomal movement, even enabling imaging in tumor-bearing mice over 11 days. The strong fluorescence signal, high stability, and long-term tracking capability indicate that PDB has tremendous potential in monitoring biological processes.

An artificial intelligence handheld sensor for direct reading of nickel ion and ethylenediaminetetraacetic acid in food samples using ratiometric fluorescence cellulose paper microfluidic chip.

User-friendly in-field sensing protocol is crucial for the effective tracing of intended analytes under less-developed countries or resources-limited environments. Nevertheless, existing sensing strategies require professional technicians and expensive laboratory-based instrumentations, which are not capable for point-of-care on-site analyses. To address this issue, artificial intelligence handheld sensor has been designed for direct reading of Ni2+ and EDTA in food samples. The sensing platform incorporates smartphone with machine learning-driven application, 3D-printed handheld device, and cellulose paper microfluidic chip stained with ratiometric red-green-emission carbon dots (CDs). Intriguingly, Ni2+ introduction makes green fluorescent (FL) of CDs glow but red FL fade because of the coordination of Ni2+ with CDs verified by density functional theory (DFT), concurrently manifesting continuous FL colour transition from red to green. Subsequent addition of EDTA renders FL of CDs-Ni2+ recover owing to the capture of Ni2+ from CDs by EDTA based on strong chelation effect of EDTA on Ni2+ confirmed via DFT, accompanying with a noticeable colour returning from green to red. Inspired by above FL phenomena, CDs-based cellulose paper microfluidic chips are first fabricated to facilitate point-of-care testing of Ni2+ and EDTA. Designed fully-automatic handheld sensor is utilized to directly output Ni2+ and EDTA concentration in water, milk, spinach, bread, and shampoo based on wide linear ranges of 0-48 µM and 0-96 µM, and low limits of detection of 0.274 µM and 0.624 µM, respectively. The proposed protocol allows for speedy straightforward on-site determination of target analytes, which will trigger the development of automated and intelligent sensors in near future.

Facile synthesis of long-wavelength emission carbon dots for hypochlorite sensing and intracellular pH imaging.

Hypochlorite (ClO-), a typical reactive oxygen species, plays an irreplaceable roles in various biological processes. In this work, long-wavelength emission carbon dots (LW-CDs) were fabricated through one-step hydrothermal method by using l-cysteine (cys) and neutral red (NR) as precursors for monitoring of hypochlorite and intracellular pH. Characterizations of as-prepared LW-CDs showed that they had excellent water solubility, high optical stability and sensitive response behavior. Fluorescence intensity of LW-CDs decayed in the presence of ClO- linearly from 10 to 162.5 µM (LOD = 1.021 µM) based on static quenching effect with ideal selectivity. Besides, LW-CDs revealed a pH responsive behavior in the pH range of 2.0 to 10.0, exhibited dual good linear relationships in the pH ranges of 4.2-5.8 and 5.8-7.4. The LW-CDs can also be utilized as imaging reagents in Hela living cells owing excellent biocompatibility and low cytotoxicity. These results demonstrated that the as-mentioned LW-CDs are expected to serve as excellent long wavelength emitting nanomaterials for fluorescence sensing and monitoring of cell fluctuations.

Novel ratiometric fluorescent probe with large Stokes shift for selective sensing and imaging of Zn2+ in live cell.

A novel ratiometric fluorescent probe, namely 5-[(3-dicyanoylidene -5.5-dimethyl) cyclohexenyl-1-ethenyl] salicylaldehyde-3'-hydroxybenzohydrazone (DCSH) is presented for the selective sensing of Zn2+ ion in acetonitrile/water (2/3, pH 7.4) solution. Introducing Zn2+ ions notably caused the peak emission of DCSH to shift from 560 nm to 646 nm, accompanied with a significant enhancement of its intensity. A vivid change in fluorescence color from yellow to red facilitated the immediate identification of Zn2+ ions by visual observation. DCSH exhibits substantial Stokes shifts (110 and 196 nm), rapid detection capability (within 10 s) and high sensitivity to Zn2+ ions, achieving a limit of detection of 31.2 nM. The response mechanism is supposed to involve the block of C = N bond isomerization and excited state intramolecular proton transfer (ESIPT) along with the enhancement of fluorescence through chelation (CHEF) effect. DCSH was effectively utilized for ratiometric fluorescence imaging to monitor exogenous Zn2+ concentrations in HeLa cells. Significantly, DCSH is capable of monitoring elevated levels of Zn2+ ion during apoptosis induced by L-Buthionine sulfoximine (BSO).

Mitochondria-Targetable Near-Infrared Fluorescent Probe for Visualization of Hydrogen Peroxide in Lung Injury, Liver Injury, and Tumor Models.

Hydrogen peroxide (H2O2) overexpressed in mitochondria has been regarded as a key biomarker in the pathological processes of various diseases. However, there is currently a lack of suitable mitochondria-targetable near-infrared (NIR) probes for the visualization of H2O2 in multiple diseases, such as PM2.5 exposure-induced lung injury, hepatic ischemia-reperfusion injury (HIRI), nonalcoholic fatty liver (NAFL), hepatic fibrosis (HF), and malignant tumor tissues containing clinical cancer patient samples. Herein, we conceived a novel NIR fluorescent probe (HCy-H2O2) by introducing pentafluorobenzenesulfonyl as a H2O2 sensing unit into the NIR hemicyanine platform. HCy-H2O2 exhibits good sensitivity and selectivity toward H2O2, accompanied by a remarkable "turn-on" fluorescence signal at 720 nm. Meanwhile, HCy-H2O2 has stable mitochondria-targetable ability and permits monitoring of the up-generated H2O2 level during mitophagy. Furthermore, using HCy-H2O2, we have successfully observed an overproduced mitochondrial H2O2 in ambient PM2.5 exposure-induced lung injury, HIRI, NAFL, and HF models through NIR fluorescence imaging. Significantly, the visualization of H2O2 has been achieved in both tumor-bear mice as well as surgical specimens of cancer patients, making HCy-H2O2 a promising tool for cancer diagnosis and imaging-guided surgery.

Bovine Serum Albumin Template-Mediated Fabrication of Ruthenium Dioxide/Multiwalled Carbon Nanotubes: High-Performance Electrochemical Dopamine Biosensing in Human Serum.

The presence of abnormal dopamine (DA) levels may cause serious neurological disorders, therefore, the quantitative analysis of DA and its related research are of great significance for ensuring health. Herein, the bovine serum albumin (BSA) template method has been proposed for the preparation of catalytically high-performance ruthenium dioxide/multiwalled carbon nanotube (RuO2/MWCNT) nanocomposites. The incorporation of MWCNTs has improved the active surface area and conductivity while effectively preventing the aggregation of RuO2 nanoparticles. The outstanding electrocatalytic performance of RuO2/MWCNTs has promoted the electro-oxidation of DA at neutral pH. The electrochemical sensing platform based on RuO2/MWCNTs has demonstrated a wide linear range (0.5 to 111.1 µM), low detection limit (0.167 µM), excellent selectivity, long-term stability, and good reproducibility for DA detection. The satisfactory recovery range of 94.7% to 103% exhibited by the proposed sensing podium in serum samples signifies its potential for analytical applications. The aforementioned results reveal that RuO2/MWCNT nanostructures hold promising aptitude in the electrochemical sensor to detect DA in real samples, further offering broad prospects in clinical and medical diagnosis.

Hydrophobic carbon quantum dots with red fluorescence: An optical dual-mode and smartphone imaging sensor for identifying Chinese Baijiu quality.

Chinese Baijiu (Liquor) is a popular alcoholic beverage, and the ethanol content in Baijiu is closely related to its quality; therefore, it is of great significance to explore a facile, sensitive, and rapid method to detect ethanol content in Baijiu. Hydrophobic carbon quantum dots (H-CQDs) with bright red fluorescence (24.14 %) were fabricated by hydrothermal method using o-phenylenediamine, p-aminobenzoic acid, manganese chloride, and hydrochloric acid as reaction precursors. After the introduction of ultrapure water into the ethanol solution dissolved with H-CQDs, the aggregated H-CQDs resulted in significant changes in fluorescence intensity and absorbance. On this basis, a sensor for detecting ethanol by optical dual-mode and smartphone imaging was constructed. More importantly, the sensor can be used for detecting ethanol content in Chinese Baijiu with satisfactory results. This sensing platform has great potential for quality identification in Chinese Baijiu, broadening the application scope of CQDs in food safety detection.

Visualization of polarity changes in endoplasmic reticulum (ER) autophagy and rheumatoid arthritis mice with near-infrared ER-targeted fluorescent probe.

The crucial cellular activities for maintaining normal cell functions heavily rely on the polarity of the endoplasmic reticulum (ER). Understanding how the polarity shifts, particularly in the context of ER autophagy (ER-phagy), holds significant promise for advancing knowledge of disorders associated with ER stress. Herein, a polarity-sensitive fluorescent probe CDI was easily synthesized from the condensation reaction of coumarin and dicyanoisophorone. CDI was composed of coumarin as the electron-donating moiety (D), ethylene and phenyl ring as the π-conjugation bridge, and malononitrile as the electron-accepting moiety (A), forming a typical D-π-A molecular configuration that recognition in the near-infrared (NIR) region. The findings suggested that as the polarity increased, the fluorescence intensity of CDI decreased, and it was accompanied by a redshift of emission wavelength at the excitation wavelength of 524 nm, shifting from 641 nm to 721 nm. Significantly, CDI exhibited a notable ability to effectively target ER and enabled real-time monitoring of ER-phagy induced by starvation or drugs. Most importantly, alterations in polarity can be discerned through in vivo imaging in mice model of rheumatoid arthritis (RA). CDI has been proven effective in evaluating the therapeutic efficacy of drugs for RA. ER fluorescent probe CDI can be optically activated in lysosomes, providing a sensitive tool for studying ER-phagy in biology and diseases.

Bridging biological and food monitoring: A colorimetric and fluorescent dual-mode sensor based on N-doped carbon dots for detection of pH and histamine.

Rapid and sensitive monitoring of pH and histamine is crucial for bridging biological and food systems and identifying corresponding abnormal situations. Herein, N-doped carbon dots (CDs) are fabricated by a hydrothermal method employing dipicolinic acid and o-phenylenediamine as precursors. The CDs exhibit colorimetric and fluorescent dual-mode responses to track pH and histamine variations in living cells and food freshness, respectively. The aggregation-induced emission enhancement and intramolecular charge transfer result in a decrease in absorbance and an increase in fluorescence, which become readily apparent as the pH changes from acidic to neutral. This property enables precise differentiation between normal and cancerous cells. Furthermore, given the intrinsic basicity of histamine, pH-responsive CDs are advantageous for additional colorimetric and fluorescent monitoring of histamine in food freshness, achieving linearities of 25-1000 µM and 30-1000 µM, respectively, which are broader than those of alternative nanoprobes. Interestingly, the smartphone-integrated sensing platform can portably and visually evaluate pH and histamine changes due to sensitive color changes. Therefore, the sensor not only establishes a dynamic connection between pH and histamine for the purposes of biological and food monitoring, but also presents a novel approach for developing a multifunctional biosensor that can accomplish environmental monitoring and biosensing simultaneously.

A novel pH-sensitive hemi-cyanine containing tetrahydropyridine ring near-infrared fluorescence probe with lysosome-targeting ability.

In recent years, hemi-cyanine dyes have been widely used as biological probes due to their red-light emission characteristics and high fluorescence quantum yield. In this study, we synthesized a novel hemi-cyanine dye containing a tetrahydropyridine ring. A lysosomal target was introduced into its structure to create a new pH-sensitive near-infrared fluorescent probe that successfully targeted lysosomes. The results showed that when the probe solution was excited at the absorption wavelength of 650 nm, its fluorescence emission wavelength was about 700 nm, and the peak intensity changed with different pH values in a wide range. Therefore, this probe enabled non-invasive detection of changes in the acidic environment of lysosomes in living organisms and showed good imaging capabilities. Moreover, the probe displays high sensitivity and good stability. The theoretical calculation of a probe structure has also been completed to discuss the relationship between structure and property.

A specific dual-locked fluorescence probe to visualize the dynamic changes of lipid droplets and hypochlorous acid in inflammation.

Inflammation is a key factor leading to the occurrence and development of many diseases, both lipid droplets (LDs) and hypochlorous acid (HClO/ClO-) are regarded as the important biomarkers of inflammation. Therefore, it is of great significance to develop an efficient single chemical sensor that can simultaneously detect these two biomarkers. To achieve the goal, we developed a dual-locked fluorescence probe (TPA-DNP) by fusing two targets activated reporting system, its implementation was achieved by turning-on the fluorescence of TPA-DNP through LDs and HClO/ClO- simultaneously. In simulated LDs environment, TPA-DNP displayed excellent selectivity to HClO/ClO-, high sensitivity (LOD = 0.527 µM) and strong anti-interference ability. In addition, cell and zebrafish imaging experiments showed that TPA-DNP could be utilized to visualize exogenous/endogenous HClO/ClO- in LDs environment, and could also be used to observe the impact of LDs changes on the HClO/ClO- detection. On the basis, TPA-DNP served as a favorable tool to achieve visualization of inflammatory dynamic changes.

Design of a dual-mode ratiometric fluorescent probe via MOF-on-MOF strategy for Al (III) and pH detection.

BACKGROUND: The construction of ratiometric fluorescent MOF sensors with integrated self-calibration and dual-channel detection can efficiently overcome the deficiencies of single-signal sensing. In this regard, the rational design of structurally functionalized MOFs is paramount for enhancing their performance in ratiometric fluorescent sensors. Lately, the concept of MOF-on-MOF design has garnered notable interest as a potential strategy for regulating the structural parameters of MOFs by integrating two or more distinct MOF types. Great efforts have been dedicated to exploring new MOF-on-MOF hybrids and developing their applications in diverse fields. Even so, these materials are still in the stage of advancement in the sensing field. RESULTS: Herein, a Zr-based metal-organic framework anchored on a rare-earth metal-organic framework (UiO-66(OH)2@Y-TCPP) was prepared for the ratiometric fluorescence detection toward Al (III) and pH. In this probe, the UiO-66(OH)2 featured hydroxyl active sites for Al (III), leading to a significant enhancement in fluorescence intensity upon the addition of Al (III), while the signal emitted by the red-emitting Y-TCPP, serving as the reference, remained constant. UiO-66(OH)2@Y-TCPP exhibited excellent selectivity for Al (III) sensing with a wider linear range of 0.1-1000 µM, and a lower detection limit of 0.06 µM. This probe has also been utilized for the quantitative determination of Al (III) in hydrotalcite chewable tablets with satisfactory results. In addition, the probe realized ratiometric pH sensing in the range of 7-13 using UiO-66(OH)2 as an interior reference. The paper-based probe strip was developed for visual pH sensing. By installing color recognition and processing software on a smartphone, real-time and convenient pH sensing could be achieved. SIGNIFICANCE: This is the first ratiometric fluorescent sensor for Al (III) and pH detection based on a MOF-on-MOF composite probe, which yields two different response modes. The detection results of Al (III) in hydrotalcite chewable tables and smartphone imaging for pH test paper demonstrate the practicability of the probe. This work opens up a new outlook on constructing a multi-functional application platform with substantial potential for employment in environmental and biological analysis tasks.

Aptamer-Modified Tetrahedral DNA Nanostructures as Drug Delivery System for Cancer Targeted Therapy.

Improving the selective delivery and uptake efficiency of chemotherapeutic drugs remains a challenge for cancer-targeted therapy. In this work, a DNA tetrahedron is constructed as a targeted drug delivery system for efficient delivery of doxorubicin (Dox) into cancer cells. The DNA tetrahedron is composed of a tetrahedral DNA nanostructure (TDN) with two strands of AS1411 aptamer as recognition elements which can target the nucleolin protein on the cell membrane of cancer cells. The prepared DNA tetrahedron has a high drug-loading capacity and demonstrates pH-responsive Dox release properties. This enables efficient delivery of Dox into targeted cancer cells while reducing side effects on nontarget cells. The proposed drug delivery system exhibits significant therapeutic efficacy in vitro compared to free Dox. Accordingly, this work provides a good paradigm for developing a targeted drug delivery system for cancer therapy based on DNA tetrahedrons.

A sensitive "turn-on" Schiff-base fluorescent probe for the selective detection of Fe3+ and bio-imaging.

A novel Schiff-base fluorescent probe, 4-(N-(2- hydroxyl-1-naphthalymethylimino)-ethylamino) -7-nitro-1,2,3-benzoxadiazole (HENB) was synthesized and utilized for spectral sensing of Fe3+ ions at neutral pH. The binding of Fe3+ to HENB in C2H5OH-HEPES buffer (1:1 v/ v, 25 mM, pH 7.2) resulted in a pronounced emission enhancement at 530 nm, which is possibly due to the inhibition of photo-induced electron transfer (PET) process as well as the chelation enhanced fluorescence (CHEF) effect. HENB shows good selectivity and sensitivity toward Fe3+ with the detection limit as low as 4.51 nM. Test strips made of HENB was used for rapid "naked-eye" detection of Fe3+ ions in aqueous medium. Moreover, HENB was successfully applied in fluorescence imaging of exogenous and endogenous Fe3+ in live Hela cells as well as zebrafish. Importantly, HENB is capable of effectively monitoring the variations of Fe3+ in living cells during ferroptosis process.

A novel multi-functional fluorescent probe for dual-channel detection of SO2 and Hg2+ and dynamic visualization of SO2 fluctuations in vivo upon mercury exposure.

Although there are many drugs used for the treatment of mercury poisoning, it is remains confused that pathological symptoms associated with Hg2+-induced oxidative stress. It is reported that SO2 can be generated as the anti-oxidant, and plays an important role in maintaining redox balance in cells. There has not yet been a study to precisely track the changes in SO2 during mercury ion poisoning. We developed a novel dual-response fluorescence probe (CY-SPH) for respective or successive determination of Hg2+ and SO2 in neutral aqueous media. The nucleophilic addition of HSO3- toward CY-SPH caused a significant fluorescence enhancement at 455 nm while the Hg2+ -triggered desulfurization of CY-SPH to the final phenolic product (CY-OH) elicited a markedly enhanced emission at 760 nm, allowing for two-color visualization of Hg2+ and SO2 with good selectivity (detection limit: 67.2 nM for Hg2+ and 34.7 nM for SO2). Moreover, CY-OH could undergo further nucleophilic addition reaction with HSO3- and resulted in a decrease in emission at 760 nm and an increase in emission at 438 nm, enabling the ratiometric determination of SO2 with better sensitivity (detection limit, 3.50 nM). Significantly, CY-SPH can monitor the endogenous SO2 fluctuations upon mercury exposure by means of confocal fluorescence imaging, which may prove valuable for deciphering the relationship between SO2 levels and the mercury induced oxidative stress. We anticipated that this research will promote to understand the functions of SO2 under the oxidative stress by Hg2+.

Ultrasensitive Electrochemical Platform for Dopamine Detection Based on CoNi-MOF@ERGO Composite.

An electrochemical sensor applied for dopamine (DA) detection was constructed. An easy static way was used to synthesize bimetallic CoNi-MOF. Next, it was mixed with graphene oxide (GO) under ultrasound to get a uniform suspension. Subsequently, the solution was coated on the glassy carbon electrode (GCE) to form CoNi-MOF@ERGO/GCE by the electrochemical reduction method. The interaction between CoNi-MOF and electrochemically reduced graphene oxide (ERGO) enhances the electrocatalytic performance for DA detection. CoNi-MOF@ERGO/GCE has a wider linear range (0.1-400 µM) and a lower detection limit (0.086 µM) under optimum conditions. Furthermore, it has been applied to test DA in human serum samples. The results reveal that the DA sensor shows excellent performance, which will provide a novel idea for more sensitive and quicker DA detection.

Drug-Primed Self-Assembly of Platinum-Single-Atom Nanozyme to Regulate Cellular Redox Homeostasis Against Cancer.

Single-atom nanozymes (SAzymes) with high catalytic activity exhibit the potential to disequilibrate the reactive oxygen metabolic balance in the tumor microenvironment (TME), which contains several endogenous reductive substances such as glutathione (GSH). Herein, a novel nano-assembly (CDs@Pt SAs/NCs@DOX) is first constructed using drug-primed platinum (Pt) single-atom or nanocluster nanozymes with a Pt loading of 34.8%, which exhibits prominent dual enzymatic activities to mimic peroxidase (POD) and glutathione oxidase (GSHOx). The unique GSHOx-like activity can efficiently scavenge GSH with a relatively low Km (1.04 mm) and high Vmax (7.46 × 10-6  m s-1 ), thus avoiding single oxygen (1 O2 ) depletion. CDs@Pt SAs/NCs@DOX simultaneously demonstrates low-temperature photothermal therapy and TME- or laser-controlled disassembly and drug release, which can effectively regulate cellular redox homeostasis and achieve high tumor growth inhibition. These outcomes may provide promising strategies for the preparation of Pt SAzymes with multiple activities and variable-sized nano-assemblies, allowing for broader applications of SAzymes and nano-assemblies in the biomedical field.