Stabilizing Dye-Sensitized Upconversion Hybrids by Cyclooctatetraene.

Lanthanide-doped upconversion nanoparticles (UCNPs) can convert low-energy near-infrared (NIR) light into high-energy visible light, making them valuable for broad applications. UCNPs often suffer from poor light-harvesting capabilities, which can be significantly improved by incorporating organic dye antennas. However, the dye-sensitized upconversion systems are prone to severe photobleaching in an ambient atmosphere. Here, we present a synergistic approach to mitigate photobleaching by introducing triplet state quencher cyclooctatetraene (COT). COT effectively suppresses the generation of singlet oxygen by quenching the triplet states of the dye and consumes the existing singlet oxygen through oxidant reactions. The inclusion of COT extends the half-life of IR806 by 4.7-times by preventing the oxidation of its poly(methylene) chains. Without significantly affecting emission intensity and dynamics, COT effectively stabilized dye-UCNPs, demonstrating a notable 3.9-fold increase in half-life under continuous laser irradiation. Our findings suggest a new strategy to enhance the photostability of near-infrared dyes and dye-sensitized upconversion nanohybrids.

3D-printed aerogels as theranostic implants monitored by fluorescence bioimaging.

Aerogel scaffolds are nanostructured materials with beneficial properties for tissue engineering applications. The tracing of the state of the aerogels after their implantation is challenging due to their variable biodegradation rate and the lack of suitable strategies capable of in vivo monitoring the scaffolds. Upconversion nanoparticles (UCNPs) have emerged as advanced tools for in vitro bioimaging because of their fluorescence properties. In this work, highly fluorescent UCNPs were loaded into aerogels to obtain theranostic implants for tissue engineering and bioimaging applications. 3D-printed alginate-hydroxyapatite aerogels labeled with UCNPs were manufactured by 3D-printing and supercritical CO2 drying to generate personalize-to-patient aerogels. The physicochemical performance of the resulting structures was evaluated by printing fidelity measurements, nitrogen adsorption-desorption analysis, and different microscopies (confocal, transmission and scanning electron microscopies). Stability of the aerogels in terms of physicochemical properties was also tested after 3 years of storage. Biocompatibility was evaluated in vitro by different cell and hemocompatibility assays, in ovo and in vivo by safety and bioimaging studies using different murine models. Cytokines profile, tissue index and histological evaluations of the main organs unveiled an in vivo downregulation of the inflammation after implantation of the scaffolds. UCNPs-decorated aerogels were first-time manufactured and long-term traceable by fluorescence-based bioimaging until 3 weeks post-implantation, thereby endorsing their suitability as tissue engineering and theranostic nanodevices (i.e. bifunctional implants).

"Three birds, one stone" strategy of NIR-responsive CO/H2S dual-gas Nanogenerator for efficient treatment of osteoporosis.

Osteoporosis (OP), the most prevalent bone degenerative disease, has become a significant public health challenge globally. Current therapies primarily target inhibiting osteoclast activity or stimulating osteoblast activation, but their effectiveness remains suboptimal. This paper introduced a "three birds, one stone" therapeutic approach for osteoporosis, employing upconversion nanoparticles (UCNPs) to create a dual-gas storage nanoplatform (UZPA-CP) targeting bone tissues, capable of concurrently generating carbon monoxide (CO) and hydrogen sulfide (H2S). Through the precise modulation of 808 nm near-infrared (NIR) light, the platform could effectively control the release of CO and H2S in the OP microenvironment, and realize the effective combination of promoting osteogenesis, inhibiting osteoclast activity, and improving the immune microenvironment to achieve the therapeutic effect of OP. High-throughput sequencing results further confirmed the remarkable effectiveness of the nanoplatform in inhibiting apoptosis, modulating inflammatory response, inhibiting osteoclast differentiation and regulating multiple immune signaling pathways. The gas storage nanoplatform not only optimized the OP microenvironment with the assistance of NIR, but also restored the balance between osteoblasts and osteoclasts. This comprehensive therapeutic strategy focused on improving the bone microenvironment, promoting osteogenesis and inhibiting osteoclast activity provides an ideal new solution for the treatment of metabolic bone diseases.

Rapid determination for tyrosine isomers in food based on N-acetyl-L-cysteine/Upconversion nanomaterials target-induced quench by chiral Electrochemiluminescence sensor.

Rapid determination of amino acid isomer is very important for the evaluation of the amino acid nutrition in different foods, so a fast and sensitive electrochemiluminescence (ECL) sensor was innovatively fabricated for the determination of tyrosine isomers in foods based on N-Acetyl-L-cysteine/upconversion nanomaterials possessed a good particular selectivity to L-tyrosine. Under the optimal conditions, for L-tyrosine, the limit of detection (LOD) of the sensor for L-tyrosine was 2.87 × 10-6 M, detection range of 5.5 × 10-5-5.5 × 10-3 M, for D-tyrosine, LOD was 2.56 × 10-5 M, detection range was from 5.5 × 10-4 to 5.5 × 10-3 M. The developed chiral sensor was used to determinate the tyrosine isomers in foods successfully, which provided a convenient method to quickly evaluate the nutritional value of amino acids in food.

Nucleic acid-functionalized upconversion luminescence biosensor based on strand displacement-mediated signal amplification for the detection of trivalent chromium ions.

BACKGROUND: Rapid industrial development has generated serious pollution, including the presence of toxic and harmful heavy metal ions. Among them, trivalent chromium ion (Cr3+) is a very important element that poses a threat to life and health in our industrial wastewater pollution. Thus, it is important to develop efficient fluorescence methods for Cr3+ detection. In this study, an upconversion luminescence biosensor for detecting Cr3+ was constructed based on a DNAzyme, strand displacement reaction (SDR), and DNA-functionalized upconversion nanoparticles (UCNPs). RESULTS: The sulfonate-rich poly (sodium 4-styrene sulfonate) (PSS) was modified onto the surface of UCNPs, forming UCNPs@PSS. Then, NH2-Capture probe DNA (NH2-Cp) was further modified onto the UCNPs@PSS surface through sulfonylation, resulting in UCNPs@PSS@NH2-Cp. The DNAzyme activated by Cr3+ triggered the release of the primer probe (Pp), which initiated the SDR system cycle, thereby releasing a tetramethylrhodamine (TAMRA)-modified signal probe (TAMRA-Sp). Finally, UCNPs@PSS@NH2-Cp bound to TAMRA-Sp through complementary base pairing, causing UCNPs and TAMRA to approach each other. Because of the luminescence resonance energy transfer (LRET) mechanism, the upconversion luminescence (UCL) signal of the UCNPs was quenched by TAMRA, enabling the detection of Cr3+ by the change of I585/I545 ratio. This biosensor has good stability, selectivity, and sensitivity, with a linear range of 0.5-75 nM and a detection limit of 0.135 nM for Cr3+. SIGNIFICANCE AND NOVELTY: Firstly, based on LRET between UCNPs and TAMRA, the quantitative analysis of Cr3+ is achieved through the changes of ratio fluorescence. Secondly, the specificity of the biosensor is improved by utilizing the specific recognition of DNA enzymes. Thirdly, the signal amplification technology of the SDR cycle greatly improves the sensitivity of biosensor. This biosensor will be useful for future environmental safety monitoring and biopsy of biological fluids.

Engineering an upconversion fluorescence sensing platform with "off-on" pattern through specific DNAzyme-mediated signal amplification for supersensitive detection of uranyl ion.

An upconversion fluorescence sensing platform was developed with upconversion nanoparticles (UCNPs) as energy donors and gold nanoparticles (AuNPs) as energy acceptors, based on the FRET principle. They were used for quantitative detection of uranyl ions (UO22+) by amplifying the signal of the hybrid chain reaction (HCR). When UO22+ are introduced, the FRET between AuNPs and UCNPs can be modulated through a HCR in the presence of high concentrations of sodium chloride. This platform provides exceptional sensitivity, with a detection limit as low as 68 pM for UO22+ recognition. We have successfully validated the reliability of this method by analyzing authentic water samples, achieving satisfactory recoveries (89.00%-112.50%) that are comparable to those of ICP-MS. These results indicate that the developed sensing platform has the capability to identify trace UO22+ in complex environmental samples.

Upconversion nanoparticles-CuMnO2 nanoassemblies for NIR-excited imaging of reactive oxygen species in vivo.

Here, we designed a ratiometric luminescent nanoprobe based on lanthanide-doped upconversion nanoparticles-CuMnO2 nanoassemblies for rapid and sensitive detection of reactive oxygen species (ROS) levels in living cells and mouse. CuMnO2 nanosheets exhibit a wide absorption range of 300-700 nm, overlapping with the visible-light emission of upconversion nanoparticles (UCNPs), resulting in a significant upconversion luminescence quenching. In an acidic environment, H2O2 can promote the redox reaction of CuMnO2, leading to its dissociation from the surface of UCNPs and the restoration of upconversion luminescence. The variation in luminescence intensity ratio (UCL475/UCL450) were monitored to detect ROS levels. The H2O2 nanoprobe exhibited a linear response in the range of 0.314-10 µM with a detection limit of 11.3 nM. The biological tests proved the excellent biocompatibility and low toxicity of obtained UCNPs-CuMnO2 nanoassemblies. This ratiometric luminescent nanoprobe was successfully applied for the detection of exogenous and endogenous ROS in live cells as well as in vivo ROS quantitation. The dual transition metal ions endow this probe efficient catalytic decomposition capabilities, and this sensing strategy broadens the application of UCNPs-based nanomaterials in the field of biological analysis and diagnosis.

NIR-triggered NO production combined with photodynamic therapy for tumor treatment.

Photodynamic therapy (PDT), as one of the most promising cancer therapy methods, is still limited by several drawbacks, such as tissue hypoxia and shallow light penetration of blue-violet light (200-450 nm), and red light (750 nm) is more penetrating to tissues than blue-violet light, but still lower than near-red light (750-1350 nm). Therefore, we proposed a synergistic therapy system by combining the near-infrared light-triggered PDT with nitric oxide (NO)-based gas therapy to enhance the anti-tumor effects. Upconversion nanoparticles (UCNPs) were loaded with the photosensitizers of ZnPc and the NO donors of l-arginine (L-Arg) to obtain the nanocomposites of UCN@mSiO2@ZnPc@L-Arg. Under 980 nm laser irradiation, reactive oxygen species (ROS) could be produced for PDT and react with l-Arg to produce NO, which is previously reported to have a greater killing effect on tumor cells than ROS and also plays an important role in promoting PDT in our study. Both the in vitro and in vivo tests demonstrated that the combined therapy of PDT with NO therapy could enhance the tumor killing effect significantly compared with the unique application of PDT. The UCNPs-based nanocomposites are expected to be widely used in biomedicine for tumor inhibition.

A Spatiotemporally Controlled Gene-Regulation Strategy for Combined Tumor Therapy Based on Upconversion Hybrid Nanosystem.

The lack of precise spatiotemporal gene modulation and therapy impedes progress in medical applications. Herein, a 980 nm near-infrared (NIR) light-controlled nanoplatform, namely URMT, is developed, which can allow spatiotemporally controlled photodynamic therapy and trigger the enzyme-activated gene expression regulation in tumors. URMT is constructed by engineering an enzyme-activatable antisense oligonucleotide, which combined with an upconversion nanoparticle (UCNP)-based photodynamic nanosystem, followed by the surface functionalization of triphenylphosphine (TPP), a mitochondria-targeting ligand. URMT allows for the 980 nm NIR light-activated generation of reactive oxygen species, which can induce the translocation of a DNA repair enzyme (namely apurinic/apyrimidinic endonuclease 1, APE1) from the nucleus to mitochondria. APE1 can recognize the basic apurinic/apyrimidinic (AP) sites in DNA double-strands and perform cleavage, thereby releasing the functional single-strands for gene regulation. Overall, an augmented antitumor effect is observed due to NIR light-controlled mitochondrial damage and enzyme-activated gene regulation. Altogether, the approach reported in this study offers high spatiotemporal precision and shows the potential to achieve precise and specific gene regulation for targeted tumor treatment.

Cellular Uptake of Upconversion Nanoparticles Based on Surface Polymer Coatings and Protein Corona.

Upconversion nanoparticles (UCNPs) are materials that provide unique advantages for biomedical applications. There are constantly emerging customized UCNPs with varying compositions, coatings, and upconversion mechanisms. Cellular uptake is a key parameter for the biological application of UCNPs. Uptake experiments have yielded highly varying results, and correlating trends between cellular uptake with different types of UCNP coatings remains challenging. In this report, the impact of surface polymer coatings on the formation of protein coronas and subsequent cellular uptake of UCNPs by macrophages and cancer cells was investigated. Luminescence confocal microscopy and elemental analysis techniques were used to evaluate the different coatings for internalization within cells. Pathway inhibitors were used to unravel the specific internalization mechanisms of polymer-coated UCNPs. Coatings were chosen as the most promising for colloidal stability, conjugation chemistry, and biomedical applications. PIMA-PEG (poly(isobutylene-alt-maleic) anhydride with polyethylene glycol)-coated UCNPs were found to have low cytotoxicity, low uptake by macrophages (when compared with PEI, poly(ethylenimine)), and sufficient uptake by tumor cells for surface-loaded drug delivery applications. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) studies revealed that PIMA-coated NPs were preferentially internalized by the clathrin- and caveolar-independent pathways, with a preference for clathrin-mediated uptake at longer time points. PMAO-PEG (poly(maleic anhydride-alt-1-octadecene) with polyethylene glycol)-coated UCNPs were internalized by energy-dependent pathways, while PAA- (poly(acrylic acid)) and PEI-coated NPs were internalized by multifactorial mechanisms of internalization. The results indicate that copolymers of PIMA-PEG coatings on UCNPs were well suited for the next-generation of biomedical applications.

Construction of UCNPs-aptamer-AuNPs luminescence energy transfer probe for ratio detection of Staphylococcus aureus.

A ratio luminescence probe was developed for detecting Staphylococcus aureus (S. aureus) based on luminescence energy transfer (LET) using double-wavelength emission (550 nm and 812 nm) upconversion nanoparticles (UCNPs) as donor, gold nanoparticles (AuNPs) as acceptor and the aptamer for S. aureus as the specific recognition and link unit. The LET process could cause luminescence quenching because of the spectral overlap between the acceptor and the donor at 550 nm. In the presence of S. aureus, S. aureus selectively combined with the aptamer, and the AuNPs left the surface of UCNPs, which weakened the quenching effect and restored the luminescence of UCNPs. Based on this, the ratio detection was realized by monitoring the change of the luminescence signal of the probe at 550 nm and taking the luminescence signal at 812 nm as the reference signal. Crucially, the probe has a fast reaction speed, with a reaction time of 25 min, and the detection of S. aureus is realized in the concentration range of 5.0 × 103-3.0 × 105 CFU/ml, with the detection limit of 106 CFU/ml. Therefore, the ratio probe has great potential for detecting of S. aureus in food because of its high sensitivity, fast speed and good selectivity.

Strategy to Achieve a Pure Red/Green/Blue-Emitting Upconversion Luminescence for Full-Color Displays.

Multicolor tunable upconversion nanoparticles (UCNPs) have garnered attention owing to their diverse applications such as displays, imaging, and security. Typically, achieving multicolor emission from UCNPs requires complicated core/multishell nanostructures comprising a core with at least five shells. Here, we propose a strategy to achieve bright and orthogonal red (R), green (G), and blue (B) upconversion (UC) luminescence without synthesizing complicated core/quintuple-shell or core/sextuple-shell nanostructures. For achieving bright and orthogonal RGB triprimary color UC luminescence, orthogonal bicolor-emitting core/shell-structured UCNPs are synthesized and blended. Orthogonal RB, RG, and GB luminescence are achieved through photon blocking. The combination of two orthogonal bicolor-emitting UCNPs exhibits pure RGB UC luminescence and full-color tunability via manipulation of excitation laser conditions. Furthermore, we present color displays achieved with transparent UCNP-polymer composites utilizing three distinct near-infrared light wavelengths, implying that the proposed strategy for attaining RGB UC luminescence may facilitate advancements in the development of full-color volumetric displays.

NIR Light and GSH Dual-Responsive Upconversion Nanoparticles Loaded with Multifunctional Platinum(IV) Prodrug and RGD Peptide for Precise Cancer Therapy.

Platinum(II) drugs as a first-line anticancer reagent are limited by side effects and drug resistance. Stimuli-responsive nanosystems hold promise for precise spatiotemporal manipulation of drug delivery, with the aim to promote bioavailability and minimize side effects. Herein, a multitargeting octahedral platinum(IV) prodrug with octadecyl aliphatic chain and histone deacetylase inhibitor (phenylbutyric acid, PHB) at axial positions to improve the therapeutic effect of cisplatin was loaded on the upconversion nanoparticles (UCNPs) through hydrophobic interaction. Followed attachment of DSPE-PEG2000 and arginine-glycine-aspartic (RGD) peptide endowed the nanovehicles with high biocompatibility and tumor specificity. The fabricated nanoparticles (UCNP/Pt(IV)-RGD) can be triggered by upconversion luminescence (UCL) irradiation and glutathione (GSH) reduction to controllably release Pt(II) species and PHB, inducing profound cytotoxicity. Both in vitro and in vivo experiments demonstrated that UCNP/Pt(IV)-RGD exhibited remarkable antitumor efficiency, high tumor-targeting specificity, and real-time UCL imaging capacity, presenting an intelligent platinum(IV) prodrug-loaded nanovehicle for UCL-guided dual-stimuli-responsive combination therapy.

Fabrication of Erbium-Doped Upconversion Nanoparticles and Carbon Quantum Dots for Efficient Perovskite Solar Cells.

Upconversion nanoparticles (UCNPs) and carbon quantum dots (CQDs) have emerged as promising candidates for enhancing both the stability and efficiency of perovskite solar cells (PSCs). Their rising prominence is attributed to their dual capabilities: they effectively passivate the surfaces of perovskite-sensitive materials while simultaneously serving as efficient spectrum converters for sunlight. In this work, we synthesized UCNPs doped with erbium ions as down/upconverting ions for ultraviolet (UV) and near-infrared (NIR) light harvesting. Various percentages of the synthesized UCNPs were integrated into the mesoporous layers of PSCs. The best photovoltaic performance was achieved by a PSC device with 30% UCNPs doped in the mesoporous layer, with PCE = 16.22% and a fill factor (FF) of 74%. In addition, the champion PSCs doped with 30% UCNPs were then passivated with carbon quantum dots at different spin coating speeds to improve their photovoltaic performance. When compared to the pristine PSCs, a fabricated PSC device with 30% UCNPs passivated with CQDs at a spin coating speed of 3000 rpm showed improved power conversion efficiency (PCE), from 16.65% to 18.15%; a higher photocurrent, from 20.44 mA/cm2 to 22.25 mA/cm2; and a superior fill factor (FF) of 76%. Furthermore, the PSCs integrated with UCNPs and CQDs showed better stability than the pristine devices. These findings clear the way for the development of effective PSCs for use in renewable energy applications.

Near-Infrared Light-Activatable DNA Tentacles for Efficient Inhibition of Tumor Metastasis by Bio-Orthogonal Cell Assembly.

Tumor metastasis remains a major challenge in cancer management. Among various treatment strategies, immune cell-based cancer therapy holds a great potential for inhibiting metastasis. However, its wide application in cancer therapy is restricted by complex preparations, as well as inadequate homing and controllability. Herein, we present a groundbreaking approach for bioorthogonally manipulating tumor-NK (natural killer) cell assembly to inhibit tumor metastasis. Multiple dibenzocyclootyne (DBCO) groups decorated long single-stranded DNA were tail-modified on core-shell upconversion nanoparticles (CSUCNPs) and condensed by photosensitive chemical linker (PC-Linker) DNA to shield most of the DBCO groups. On the one hand, the light-triggered DNA scaffolds formed a cross-linked network by click chemistry, effectively impeding tumor cell migration. On the other hand, the efficient cellular assembly facilitated the effective communication between tumor cells and NK-92 cells, leading to enhanced immune response against tumors and further suppression of tumor metastasis. These features make our strategy highly applicable to a wide range of metastatic cancers.

Dual-mode upconversion sensors for detecting differently charged biotargets based on the oxidase-mimicking activity of Ce4+ and electrostatic control.

Heparin is a highly negatively charged sulfated linear polymer glycosaminoglycan that has been widely used as an anticoagulant in medicine. Protamine is a cationic protein rich in arginine that is used to treat the blood-brain barrier during excess heparin surgery. Trypsin is the most important digestive enzyme-encoding generated by the pancreas and can specifically cleave the carboxyl ends of arginine and lysine residues. Heparin, protamine, and trypsin interact and constrain each other, and their fluctuations reflect the body's dysfunction. Therefore, it is necessary to develop a fast, sensitive, and highly selective assay for regularly monitoring the levels of heparin, protamine, and trypsin in serum. Herein, a fluorescent and colorimetric dual-mode upconversion nanoparticle (UCNP) biosensor was used for the determination of heparin, protamine, and trypsin based on the oxidase-mimicking activity of Ce4+ and electrostatic control. The biosensor exhibited sensitive detection of heparin, protamine, and trypsin with low limits of detection (LODs) of 16 ng/mL, 87 ng/mL and 31 ng/mL, respectively. Furthermore, the designed biosensor could eliminate autofluorescence, which not only effectively increased the accuracy of the sensor but also provided a new sensing pathway for the detection of differently charged biotargets.

Natural and polyanionic heparin polysaccharide functionalized upconversion nanoparticles for highly sensitive and selective ratiometric detection of pesticide.

Pesticide contamination is a global concern, threatening human health and food safety. Herein, we developed heparin (HEP) functionalized upconversion nanoparticles (UCNPs)-based ratiometric nanosensor for the sensitive detection of 2,6-dichloro-4-nitroaniline (DCN) pesticide via inner filter effect. The strategy for HEP functionalization of UCNPs is based on adjusting the surface potentials of UCNPs with polyanionic HEP through the electrostatic interaction. UCNPs (NaYbF4:Gd/Y/Tm@NaYbF4@NaYF4) was designed with core-shell-shell structure and extra sensitizer layer for efficient and strong upconversion luminescence (UCL) in the range of UV to NIR. After incorporation of DCN, the upconverted UV emission of UCNPs-HEP ratiometric nanosensor was considerably quenched with the NIR UCL at 800 nm remaining unchanged as internal standard. The UCNPs-HEP ratiometric nanosensor can achieve outstandingly selective and sensitive detection of DCN at the wide linear range of 5-300 µM with a detection limit of 0.41 µM. The remarkable applicability of the UCNPs-HEP ratiometric nanosensor was verified in apple, cucumber and grapes samples. The developed UCNPs-HEP ratiometric nanosensor with excellent biocompatibility and water dispersion capability, is promising for convenient, selective and sensitive sensing of DCN towards food and aqueous samples.

Recent Advancement of Nanotheranostics in Cancer Applications.

The field of nanomedicine shows promising implications in the concurrent delivery of therapeutic and diagnostic (theranostics) compounds in a single platform. Nanotheranostics is incredibly promising since it offers simultaneous non-invasive disease detection and treatment together with the exciting ability to track drug release and distribution in real-time, thereby forecasting and evaluating the efficacy of the therapy. The cancer theranostic approach improves the cancer prognosis safely and effectively. Common classes of nanoscale biomaterials, including magnetic nanoparticles, quantum dots, upconversion nanoparticles, mesoporous silica nanoparticles, carbon- based nanoparticles, and organic dye-based nanoparticles, have demonstrated enormous potential for theranostic activity. The need for improved disease detection and enhanced chemotherapeutic treatments, together with realistic considerations for clinically translatable nanomaterials will be key driving factors for theranostic agent research shortly. The developments of precision theranostic nanomaterials are employed in imaging systems like, MRI, PET, and SPECT with multifunctional ability. In this review, different nanoparticles/nanomaterials that are used/developed for theranostic activity are discussed.

Upconversion-based hydrogel kit with Python-assisted analysis platform for sample-to-result detection of organophosphorus pesticide.

On-site quantitative analysis of pesticide residues is crucial for monitoring environmental quality and ensuring food safety. Herein, we have developed a reliable hydrogel portable kit using NaYbF4@NaYF4: Yb, Tm upconversion nanoparticles (UCNPs) combined with MnO2 nanoflakes. This portable kit is integrated with a smartphone reader and Python-assisted analysis platform to enable sample-to-result analysis for chlorpyrifos. The novel UCNPs maximizes energy donation to MnO2 acceptor by employing 100 % of activator Yb3+ in the nucleus for NIR excitation energy collection and confining emitter Tm3+ to the surface layer to shorten energy transfer distance. Under NIR excitation, efficient quenching of upconversion blue-violet emission by MnO2 nanoflakes occurs, and the quenched emission is recovered with acetylcholinesterase-mediated reactions. This process allows for the determination of chlorpyrifos by inhibiting enzymatic activity. The UCNPs/MnO2 were embedded to fabricate a hydrogel portable kit, the blue-violet emission images captured by smartphone were converted into corresponding gray values by Python-assisted superiority chart algorithm which achieves a real-time rapid quantitative analysis of chlorpyrifos with a detection limit of 0.17 ng mL-1. At the same time, pseudo-color images were also added by Python in "one run" to distinguish images clearly. This sensor detection with Python-assisted analysis platform provides a new perspective on pesticide monitoring and broadens the application prospects in bioanalysis.

Chemo-photodynamic antitumour therapy based on Er-doped upconversion nanoparticles coated with hypocrellin B and MnO2.

An antitumour chemo-photodynamic therapy nanoplatform was constructed based on phospholipid-coated NaYF4: Yb/Er upconversion nanoparticles (UCNPs). In this work, the amphiphilic block copolymer DSPE-PEG2000 was combined with the surface ligand oleic acid of the UCNPs through hydrophobic interaction to form liposomes with a dense hydrophobic layer in which the photosensitizer hypocrellin B (HB) was assembled. The coated HB formed J-aggregates, which caused a large redshift in the absorption spectrum and improved the quantum efficiency of energy transfer. Furthermore, MnO2 nanosheets grew in-situ on the liposomes through OMn coordination. Therefore, a multifunctional tumour microenvironment (TME)-responsive theranostic nanoplatform integrating photodynamic therapy (PDT) and chemodynamic therapy (CDT) was successfully developed. The results showed that this NIR-mediated chemo-photodynamic therapy nanoplatform was highly efficient for oncotherapy.