Coordination Polymer Nanoparticles Research Articles

Highly Conductive Two-Dimensional FeTHBQ/Graphene Nanocomposite as the Cathode Material for Lithium-Ion Batteries.

Constructing high-performance coordination polymer (CP) cathodes for lithium-ion batteries based on the redox reactions of both high-potential transition metal ions and high-capacity organic ligands has attracted extensive attention. However, CP cathodes suffer from structural degradation, low electrical conductivity, and sluggish diffusion kinetics, resulting in poor cycling stability and inferior rate capability. Herein, the ultrafine FeTHBQ (THBQ = tetrahydroxy-1,4-benzoquinone) CP nanoparticles in situ grew on both sides of graphene nanosheets to form the uniform two-dimensional (2D) FeTHBQ/Graphene nanocomposite with a sandwich structure via a one-pot solvothermal method. The highly conductive graphene skeleton promotes the electronic conduction and structural stability for the 2D FeTHBQ/Graphene nanocomposite. Besides, compared with bulk FeTHBQ, the primary FeTHBQ nanoparticles in the FeTHBQ/Graphene nanocomposite have smaller particle sizes with larger specific surface areas. This not only shortens the Li+ diffusion distance in the FeTHBQ crystal but also benefits Li+ transfer between the electrolyte and the electrode. In the FeTHBQ/Graphene nanocomposite, the active material of FeTHBQ manifested multiple redox centers of transition metal ions (Fe3+/Fe2+) and carbonyls (C═O/C-O-) in THBQ ligands. Owing to the enhancements of structural stability, electronic conduction, and Li+ diffusion kinetics, the 2D FeTHBQ/Graphene nanocomposite presented a high lithium-ion storage capacity of 217.2 mA h g-1 at 50 mA g-1, a fast rate capability of 79.1 mA h g-1 at 5000 mA g-1, and a stable cycling performance of 87.2 mA h g-1 at 500 mA g-1 after 100 cycles. This work sheds light on the great opportunity for optimizing the electrochemical performances of CP-based functional electrode materials by combining with conductive substrates.

Highly Efficient Synergistic Chemotherapy and Magnetic Resonance Imaging for Targeted Ovarian Cancer Therapy Using Hyaluronic Acid-Coated Coordination Polymer Nanoparticles.

The diagnosis and treatment of ovarian cancer (OC) are still a grand challenge, more than 70% of patients are diagnosed at an advanced stage with a dismal prognosis. Magnetic resonance imaging (MRI) has shown superior results to other examinations in preoperative assessment, while cisplatin-based chemotherapy is the first-line treatment for OC. However, few previous studies have brought together the two rapidly expanding fields. Here a technique is presented using cisplatin prodrug (Pt-COOH), Fe3+, and natural polyphenols (Gossypol) to construct the nanoparticles (HA@PFG NPs) that have a stable structure, controllable drug release behavior, and high drug loading capacity. The acidic pH values in tumor sites facilitate the release of Fe3+, Pt-COOH, and Gossypol from HA@PFG NPs. Pt-COOH with GSH consumption and cisplatin-basedchemotherapy plus Gossypol with pro-apoptotic effects displays asynergisticeffect forkillingtumorcells. Furthermore, the release of Fe3+ at the tumor sites promotes ferroptosis and enables MRI imaging of OC. Inthe patient-derived tumor xenograft (PDX)model, HA@PFG NPs alleviate the tumor activity. RNA sequencing analysis reveals that HA@PFG NPs ameliorate OC symptoms mainly through IL-6 signal pathways. This work combines MRI imaging with cisplatin-based chemotherapy, which holds great promise for OC diagnosis and synergistic therapy.

Dual-Function Nanoscale Coordination Polymer Nanoparticles for Targeted Diagnosis and Therapeutic Delivery in Atherosclerosis.

Atherosclerosis is the primary cause of cardiovascular events such as heart attacks and strokes. However, current medical practice lacks non-invasive, reliable approaches for both imaging atherosclerotic plaques and delivering therapeutic agents directly therein. Here, a biocompatible and biodegradable pH-responsive nanoscale coordination polymers (NCPs) based theranostic system is reported for managing atherosclerosis. NCPs are synthesized with a pH-responsive benzoic-imine (BI) linker and Gd3+. Simvastatin (ST), a statin not used for lowering blood cholesterol but known for its anti-inflammatory and antioxidant effects in mice, is chosen as the model drug. By incorporating ST into the hydrophobic domain of a lipid bilayer shell on NCPs surfaces, ST/NCP-PEG nanoparticles are created that are designed for dual purposes: they diagnose and treat atherosclerosis. When administered intravenously, they target atherosclerotic plaques, breaking down in the mild acidic microenvironment of the plaque to release ST, which reduces inflammation and oxidative stress, and Gd-complexes for MR imaging of the plaques. ST/NCP-PEG nanoparticles show efficacy in slowing the progression of atherosclerosis in live models and allow for simultaneous in vivo monitoring without observed toxicity in major organs. This positions ST/NCP-PEG nanoparticles as a promising strategy for the spontaneous diagnosis and treatment of atherosclerosis.

A Terbium Ion-Based Dual-Ligand Fluorescent Probe for Highly Selective and Sensitive Detection of Cu2+ Ions.

In this study, a fluorescent probe (GMP-Tb-SSA) utilizing lanthanide coordination polymer nanoparticles, GMP-Tb, as a sensing platform, and 5-sulfosalicylic acid (SSA) as a cofactor ligand was proposed for the detection of copper ions (Cu2+). GMP-Tb was synthesized by the self-assembly of guanine monophosphate (GMP) and terbium ion (Tb3+), and SSA was introduced as a sensitizer into the GMP-Tb network. Cu2+ could efficiently inhibit the electron transfer from the ligand GMP to the central ion, Tb3+, leading to a significant quench of fluorescence of Tb3+. The method is highly selective with a linear range of 0 to 21 µM and a detection limit of 300 nM. It is not interfered by metal ions, amino acids, and other species, and can be successfully applied to the detection of Cu2+ in real water samples.

Synergistic Therapeutic Effects of D-Mannitol-Cerium-Quercetin (Rutin) Coordination Polymer Nanoparticles on Acute Lung Injury.

Acute lung injury (ALI) remains a significant global health issue, necessitating novel therapeutic interventions. In our latest study, we pioneered the use of D-mannitol-cerium-quercetin/rutin coordination polymer nanoparticles (MCQ/R NPs) as a potential treatment for ALI. The MCQ/R NPs, which integrate rutin and quercetin for their therapeutic potential and D-mannitol for its pulmonary targeting, displayed exceptional efficacy. By utilizing cerium ions for optimal nanoparticle assembly, the MCQ/R NPs demonstrated an average size of less than 160 nm. Impressively, these nanoparticles outperformed conventional treatments in both antioxidative capabilities and biocompatibility. Moreover, our in vivo studies on LPS-induced ALI mice showed a significant reduction in lung tissue inflammation. This groundbreaking research presents MCQ/R NPs as a promising new approach in ALI therapeutics.

Manganese coordination polymer nanoparticles with excellent oxidase-like activity for the rapidly and selectively colorimetric detection of glutathione

Novel kinds of manganese coordination polymer nanoparticles (Mn-IMZs CPNs) were fabricated through self-assemble of imidazole with Mn2+ ions in aqueous solution. The prepared Mn-IMZs CPNs, with remarkable stability, exhibit excellent oxidase-like activity that can effectively catalyze the conversion of the dissolved O2 to O2•−, turning the colorless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxidized TMB (ox-TMB). Based on the inhibitory effect of glutathione (GSH) on the TMB oxidation, a rapid and highly sensitive colorimetric method for the detection of GSH was developed, and the linear ranges are 1.25–50 μM and 50–112.5 μM. Besides, the discriminative detection of GSH from cysteine was achieved by using the time lag between N-ethylmaleimide on the destruction of thiol compounds. Finally, the developed method was successfully applied in the quantification of GSH in tablets and rabbit plasma with high accuracy and good recovery.

Intravenous injectable metformin-Cu(II)-EGCG coordination polymer nanoparticles for electrothermally enhanced dual-drug synergistic tumor therapy.

Intravenous injectable metformin-Cu(II)-EGCG infinite coordination polymer nanoparticles (metformin-Cu(II)-EGCG ICP NPs) have been synthesized, and an efficient strategy for synergistic tumor therapy by utilizing these nanoparticles in conjunction with micro-electrothermal needles (MENs) was proposed. These nanoparticles display exceptional uniformity with a diameter of 117.5 ± 53.3 nm, exhibit an extraordinary drug loading capacity of 90% and allow for precise control over the drug ratio within the range of 1 : 1 to 1 : 20 while maintaining excellent thermal stability. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were employed to determine their chemical structure and coordination state. The combination index (CI) value of the metformin-Cu(II)-EGCG ICP NPs was calculated to be 0.19, surpassing that of the two individual drugs and metformin mixed with EGCG (0.98). Importantly, upon intravenous injection, metformin in nanoparticles demonstrated exceptional stability in the bloodstream, while both drugs were rapidly released within the acidic tumor microenvironment. Animal experiments showcased an impressive tumor inhibition rate of 100% within a mere 20-day time frame after the synergistic therapy with a lower dosage (5.0 mg kg-1 of nanoparticles), coupled with a minimal tumor recurrence rate of only 18.75% over a 60-day observation period. These findings indicate the promising prospects of these nanoparticles in tumor treatment.

Portable visual assay for anthrax biomarker based on lanthanide coordination polymer nanoparticles and smartphone-integrated mini-device

A novel portable sensor based on LML-Tb3+-AMP NPs and a custom-built device was fabricated for real-time and visual detection of anthracis biomarker.

Cobalt-based coordination polymer imitating nanozymatic Peroxido-Reductase activity for specific and sensitive detection of Fe(II) ions

Nanozyme based sensors have evolved as an equable and productive approach for detecting obnoxious metal ions in water samples. A coherent and methodical outlook for nanozymatic sensors is provided in this work. A Co(II) based coordination polymer [Co(L)1.5(ac)3]n named Co-CP, (L = N, N-(benzo-3,8-phenanthroline-2,7-diyl)diisonicotinamide and ac = CH3COO–) has been synthesized in this paper. Co(II) based coordination polymer nanoparticles (Co-CP NPs) constructed by using hand grinding process stimulates the nanozymatic action due to increased surface area and exposure of catalytically active sites. The fabricated Co-CP NPs were characterized using various sophisticated analytical techniques such as SCXRD, HRTEM, FESEM, PXRD etc. The NPs thus formed were about 27 nm in size and pertain porous sites. The Co-CP NPs exhibited peroxido-reductase mimicking activity for TMB(3,3′,5,5′-tetramethylbenzidine) oxidation. The catalytic action of the Co-CP NPs was utilized to detect Fe(II) ion selectively with a detection limit of 0.66 µM. The kinetics for the study were described using Michaelis-Menten curve. The Km and Vmax values for H2O2 and Co-CP NPs were analyzed further to access the catalytic action of Co-CP NPs. XPS and zeta potential analysis were evidenced to elucidate the detection mechanism. The compatibility and practicality of the present method was also assured by actual water samples from different sources that showed good recovery percentage. Therefore, an economical, manageable and equable approach for using CPs as a sensing tool is provided hereby.

Ultrasmall Bi/Cu Coordination Polymer Combined with Glucose Oxidase for Tumor Enhanced Chemodynamic Therapy by Starvation and Photothermal Treatment.

Multi-modal combination therapy for tumor is expected to have superior therapeutic effect compared with monotherapy. In this study, a super-small bismuth/copper-gallic acid coordination polymer nanoparticle (BCN) protected by polyvinylpyrrolidone is designed, which is co-encapsulated with glucose oxidase (GOX) by phospholipid to obtain nanoprobe BCGN@L. It shows that BCN has an average size of 1.8 ± 0.7nm, and photothermal conversion of BCGN@L is 31.35% for photothermal imaging and photothermal therapy (PTT). During the treatment process of 4T1 tumor-bearing nude mice, GOX catalyzes glucose in the tumor to generate gluconic acid and hydrogen peroxide (H2 O2 ), which reacts with copper ions (Cu2+ ) to produce toxic hydroxyl radicals (•OH) for chemodynamic therapy (CDT) and new fresh oxygen (O2 ) to supply to GOX for further catalysis, preventing tumor hypoxia. These reactions increase glucose depletion for starvation therapy , decrease heat shock protein expression, and enhance tumor sensitivity to low-temperature PTT. The in vitro and in vivo results demonstrate that the combination of CDT with other treatments produces excellent tumor growth inhibition. Blood biochemistry and histology analysis suggests that the nanoprobe has negligible toxicity. All the positive results reveal that the nanoprobe can be a promising approach for incorporation into multi-modal anticancer therapy.

An intelligent “chemical tongue” for high-order monitoring ATP-related physiological phosphates and ATP hydrolysis through diverse transduction principles

For discriminating diverse analytes and monitoring a specific chemical reaction, the emerging multi-channel “chemical nose/tongue” is challenging multi-material “chemical nose/tongue”. The former contributes greatly to integrating different transduction principles from a single sensing material, avoiding the need for complex design, high cost, and tedious operation involved with the latter. Therefore, this high-order sensing puts a particular emphasis on the effects of encapsulation. Herein, the plasmonic gold nanoparticles (Au NPs) are encapsulated as a core into the fluorescent guanine monophosphate-Tb3+ infinite coordination polymer nanoparticles (GMP-Tb ICPs) to obtain a core-shell nanocomposite named Au NPs@GMP-Tb ICPs. Hence, a dual-channel “chemical tongue” based on Au NPs@GMP-Tb ICPs is present to realize high-order sensing of adenosine triphosphate (ATP)-related physiological phosphates and the monitoring of ATP hydrolysis. Considering the affinity of Tb3+ towards P–O bonds, four inorganic phosphates and three nucleotide phosphates with different phosphate group numbers and steric hindrance effect directly regulate two stimulus responses (fluorescence intensity and UV–vis absorbance) of Au NPs@GMP-Tb ICPs. Robust statistical methods, such as linear discriminant analysis and hierarchical cluster analysis, are used to recognize each phosphate by the developed sensor array either in the aqueous solution or in complex media such as serum, together with efficiently monitored ATP hydrolysis at different intervals. These findings and blind test clarify that the designed “chemical tongue” guarantees interference resistance and strengthens analytical capacity, together with offering valuable insight into “lab-on-a-nanoparticle” development for monitoring specific chemical reactions.

High-efficiency fluorescent coordination polymer nanoparticles co-doped with Ce3+/Tb3+ ions for curcumin detection.

Curcumin (Cur) possesses diverse biological and pharmacologic effects. It is widely used as a food additive and therapeutic medicine. A study to determine a sensitive detection method for Cur is necessary and meaningful. In this work, double rare earth ions co-doped fluorescent coordination polymer nanoparticles (CPNPs) were developed for the Cur detection. The CPNPs were synthesized by using adenosine monophosphate (AMP) as bridge ligands via coordination self-assembly with Ce3+ and Tb3+. The AMP-Ce/Tb CPNPs exhibited the characteristic green fluorescence of Tb3+ and had high luminescence efficiency. Under the optimal conditions, the fluorescence intensity of AMP-Ce/Tb CPNPs could be significantly quenched by Cur. The fluorescence quenching extent at λex/λem of 300 nm/544 nm showed a good linear relationship with the Cur concentration in the range of 10 to 1000 nM. The detection limit was as low as 8.0 nM (S/N = 3). This method was successfully applied to the determination of Cur in real samples with satisfactory results. The luminescence mechanism of AMP-Ce/Tb CPNPs and the fluorescence quenching mechanism of the CPNPs by Cur were both examined.

Co-delivery of three synergistic chemotherapeutics in a core-shell nanoscale coordination polymer for the treatment of pancreatic cancer

The combination chemotherapy regimen FOLFIRINOX comprising folinic acid, 5-fluorouracil, irinotecan, and oxaliplatin is the first-line treatment for patients with advanced pancreatic cancer, but its use remains prohibitive for the majority of patients due to severe side effects. Here, we report a core-shell nanoscale coordination polymer (NCP) nanoparticle co-delivering a potent and synergistic combination of oxaliplatin, gemcitabine, and SN38 (OGS), for the treatment of pancreatic cancer in mouse models. OGS contains key synergistic components of FOLFIRINOX in a controllable drug ratio., It exhibited particle stability in blood circulation and enhanced deposition of the drugs in acidic tumor environments. In vitro, OGS showed superior cytotoxicity over free drug combinations and robust cytotoxic synergism among its three components. In vivo, OGS improved drug circulation, increased tumor deposition, and exhibited superior antitumor efficacy over the free drug combination in both subcutaneous and orthotopic pancreatic tumor models. OGS treatment achieved 75–91% tumor growth inhibition and prolonged mouse survival by 1.6- to 2.8-folds while minimizing systemic toxicities such as neutropenia, hepatotoxicity, and renal toxicity. This work uncovers a novel and clinically relevant nanomedicine strategy to co-deliver synergistic combination chemotherapies for difficult-to-treat cancers.

Integrated ratiometric luminescence sensing strategy based on encapsulation of guests in heterobinuclear lanthanide coordination polymer nanoparticles for glucose detection in human serum

Lanthanide coordination polymers (LnCPs) can be used as a host platform to encapsulate functional guest molecules for the construction of integrated sensing platforms. In this work, two guest molecules, rhodamine B (RhB) and glucose oxidase (GOx), were successfully encapsulated in a heterobinuclear lanthanide coordination polymer synthesized by self-assembly of Ce3+, Tb3+ and adenosine monophosphate (AMP) to form RhB&GOx@AMP-Tb/Ce. Both guest molecules show good storage stability and minimal leakage. The higher catalytic activity and stability of RhB&GOx@AMP-Tb/Ce is obtained due to the confinement effect compared to free GOx. RhB&GOx@AMP-Tb/Ce exhibits superior luminescence based on the internal tandem energy transfer process of the nanoparticles (Ce3+→Tb3+→RhB). Glucose can be oxidized in the presence of GOx to form gluconic acid and H2O2. Subsequently, Ce3+ in the AMP-Tb/Ce host structure can be oxidized by H2O2 to Ce4+, thereby interrupt the internal energy transfer process and cause ratiometric luminescence response. Benefiting from the synergistic effect, the smart integrated luminescent glucose probe exhibits a wide linear range (0.4–80 μM) and a low detection limit (74.3 nM) with high sensitivity, selectivity and simplicity, enabling the quantitative detection of glucose in human serum. This work describes a good strategy to construct an integrated luminescence sensor based on lanthanide coordination polymers.

Aggregation‐induced emission artificial enzyme (AIEzyme) with DNase‐like activity: Imaging and matrix cleavage for combating bacterial biofilm

AbstractDNase‐catalyzed hydrolysis of extracellular DNA (eDNA) has been widely employed to eradicate intractable biofilms. Although aggregation‐induced emission (AIE) has become the ideal tool for killing planktonic bacteria, AIE luminogens (AIEgens) often lack DNase‐mimetic activity, so as to suffer from poor anti‐biofilm capacity. Here, an “AIEzyme”, a kind of AIE nanomaterial with enzyme‐like activity, is designed and synthesized, where the AIEgens are used as the ligands of Zr‐based coordination polymer nanoparticles. Not only does AIEzyme have enduring DNase‐mimetic activity with low activation energy, but also structural rigidity‐stabilized fluorescence. Due to the long‐acting hydrolysis for eDNA in biofilm, AIEzyme can efficiently disorganize the established biofilms with good penetrability and realize the healing of superbug‐infected wounds under only one dose of AIEzyme. This work provides a strategy to endow ordinary AIEgens with DNase‐like and anti‐biofilm activities. Moreover, AIEzymes can be observed by virtue of their own AIE character, facilitating the study on self‐positioning and residual amount of AIEzymes in wounds. The concept “AIEzyme” would hopefully stimulate the tremendous expansion for the tool kits and the application of AIEgens and artificial enzymes.

Thioflavin-T-Incorporated Cerium-ATP Coordination Polymer Nanoparticles: A Promising System for Detection of Uranyl Ion (UO22+) in Aqueous Medium.

Lanthanide-based coordination polymer nanoparticles (Ln-CPNs) are studied for analytical and biomedical sensing, mainly utilizing the luminescent properties of lanthanides. However, the inclusion of fluorescent guest molecules within the nanoparticles can lead to a stimuli-responsive system with modulated photo-physical properties that can be useful for detecting analytes. In this work, we have synthesized cerium(III) coordination polymer nanoparticles using adenosine triphosphate (ATP) molecules as the ligands. The porous polymeric structure enables CPNs for reversible inclusion and release of thioflavin-T (ThT), which is a weakly emissive dye in the free state but becomes highly emissive when incorporated into the Ce-ATP CPNs. Modulation of the photo-physical properties of ThT-incorporated CPNs in response to the radiotoxic and environmentally alarming uranyl ion (UO22+) has been used for its detection in aqueous medium in the range of 0-20 μM by fluorimetry with an LOD of 80 ng mL-1 (0.34 μM) in deionized water without interference from the most commonly occurring metal ions. Furthermore, the sensing platform has been successfully utilized for UO22+ determination in seawater sample without any pre-treatment and adjustment of pH.

Visualizing stimulus-responsive dual-ligand fluorescent probes for hypochlorite: A novel strategy for real application in tap water.

As an effective ingredient of disinfectants, ClO- inevitably remains in water, which induces potential health hazards such as lung damage and kidney disease. In this study, we synthesized stimulus-responsive dual-ligand luminol-Tb-GMP coordination polymer nanoparticles (luminol-Tb-GMP CPNPs) as highly selective fluorescent probes for the real-time and visual detection of ClO- . CPNPs consist of Tb3+ , a nuclear metal, that coordinates with GMP and luminol, an auxiliary ligand. GMP can be oxidized by ClO- and damage its structure, resulting in fluorescence quenching of CPNPs. The two-ligand CPNPssensor has a rapid fluorescent response, significant fluorescent color change, and high sensitivity, with a linear range of 2-18 μM and a detection limit of 0.14 μM. It has been successfully used to detect ClO- in tap water, fountain water, and drinking water. Simultaneously, the portable filter paper strip was prepared to expand the range of applications outside the laboratory, which will provide a promising application for the real-time and semiquantitative analysis of ClO- .

Engineered procyanidin-Fe nanoparticle alleviates intestinal inflammation through scavenging ROS and altering gut microbiome in colitis mice.

Inflammatory bowel disease (IBD) is an idiopathic chronic inflammatory bowel disease characterized by inflammation, intestinal barrier injury, and imbalance of gut microbiota. Excess accumulation of reactive oxygen species (ROS) is closely correlated with the development and reoccurrence of IBD. Previous researches demonstrate that procyanidin, as a natural antioxidant, exhibits strong ability of eliminating ROS, thus showing good therapeutic effects in the inflammation-related diseases. Non-etheless, its poor stability and solubility always limits the therapeutic outcomes. Here, we typically designed an antioxidant coordination polymer nanoparticle using the engineering of procyanidin (Pc) and free iron (Fe), named Pc-Fe nanozyme, for effectively scavenging ROS and further inhibiting inflammation while altering the gut microbiome for the treatment of colitis. Furthermore, in vitro experiments uncover that Pc-Fe nanoparticles exert strong multi biomimic activities, including peroxidase, and glutathione peroxidase, for the scavenging of ROS and protecting cells from oxidative injury. In addition, the colon accumulation of Pc-Fe nanozyme effectively protects the intestinal mucosa from oxidative damage while significantly downregulates pro-inflammatory factors, repairs the intestinal barriers and alternates gut microbiome after orally administrated in sodium dextran sulfate (DSS) induced colitis mice. The results collectively illustrate that the multienzyme mimicking Pc-Fe nanozyme owns high potential for treating IBD through scavenging ROS, inhibiting inflammation, repairing gut barriers and alternating gut microbiome, which further promising its clinical translation on IBD treatment and other ROS induced intestinal diseases.

Construction of fluorescence and colorimetric tandem dual-mode sensor by modulating fluorescence and oxidase-like activity via valence switching of cerium-based coordination polymer nanoparticles for sarcosine detection.

A fluorescence and colorimetric tandem dual-mode sensor was established by modulating fluorescence and oxidase-like activity via valence switching of cerium-based coordination polymer nanoparticles (Ce-CPNs) for the detection of sarcosine (Sar) which is considered as a potential biomarker for the diagnosis of prostate cancer (PCa). In the present research, sarcosine oxidase (SOX) specifically catalyzes the oxidation of Sar to yield H2O2 which can rapidly oxidize Ce(III)-CPNs to generate Ce(IV)-CPNs in appropriate alkaline solution. The generated Ce(IV)-CPNs create a markedly weakened fluorescent signal at 350nm, while they can induce oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to generate blue TMBox through emerging good oxidase-like activity. The sensing platform can realize accurate, stable, and high-throughput detection of Sar because of the tandem dual signal output mechanism. More attractively, the chromogenic hydrogel sensing device using smartphone photographing has achieved perfect results for the on-site sensing of Sar in urine specimens without large experimental equipments, demonstrating its considerable clinical application potential in the early diagnosis of PCa.

Detecting phosphate using lysine-sensitized terbium coordination polymer nanoparticles as ratiometric luminescence probes.

Probes for detecting phosphate ions (Pi) are required for environmental monitoring and to protect human health. Here, novel ratiometric luminescent lanthanide coordination polymer nanoparticles (CPNs) were successfully prepared and used to selectively and sensitively detect Pi. The nanoparticles were prepared from adenosine monophosphate (AMP) and Tb3+, and lysine (Lys) was used as a sensitizer (through the antenna effect) to switch on Tb3+ luminescence at 488 and 544nm while Lys luminescence at 375nm was quenched because of energy transfer from Lys to Tb3+. The complex involved is here labeled AMP-Tb/Lys. Pi destroyed the AMP-Tb/Lys CPNs and therefore decreased the AMP-Tb/Lys luminescence intensity at 544nm and increased the luminescence intensity at 375nm at an excitation wavelength of 290nm, meaning ratiometric luminescence detection was possible. The ratio between the luminescence intensities at 544 and 375nm (I544/I375) was strongly associated with the Pi concentration between 0.1 and 6.0μM, and the detection limit was 0.08μM. The dual-emission reverse-change ratio luminescence sensing method can exclude environmental effects, so the proposed assay was found to be very selective. The method was successfully used to detect Pi in real water samples, and acceptable recoveries were found, suggesting that the method could be used in practice to detect Pi in water samples.