Tailored three-color quantum dots nanobeads for multiplexed detection with tunable detection range and multilevel sensitivity of signal-amplified immunosensor.

The excellent optical properties of quantum dots (QDs) make them as an ideal fluorescent probe for multiplexed detection, however, the interference between different emission spectra, the dependence of excitation wavelengths, and the sharp decrease of quantum yield (QY) during surface modification are issues that cannot be ignored. Herein, a dual protection scheme of polymer and silica was proposed to prepare high-quality three-color QDs nanobeads using QDs with different ligands. In comparison with single-core QDs, the fluorescence signal of the prepared QD nanobeads (QBs) is increased by more than 1,000 times and has better stability. Considering the excitation efficiency of QDs, we tailor three-color QBs as fluorescent probes based on fluorescence-linked immunosorbent assays (tQBs-FLISA) to detect multiple inflammatory biomarkers simultaneously with tunable detection ranges. This resulted in highly sensitive detection of three inflammatory biomarkers in comparison to the single-core QD-FLISA, the sensitivities of C-reactive protein (CRP), serum amyloid A (SAA), and procalcitonin (PCT) were increased by 16-fold, 19-fold, and 5-fold, respectively, to 0.48 ng/mL, 0.42 ng/mL, and 10 pg/mL. Furthermore, the tQBs-FLISA showed good accuracy without interference from common serum factors. In this strategy, a three-color QBs suitable for multilevel sensitivity and tunable detection range was tailored using the versatile polymer and silica dual protection method, building high-performance immunosensor for in vitro diagnostics (IVD).

Boosting Photon Emission from the Chemiluminescence of Luminol Based on Host-Guest Recognition for the Determination of Dopamine.

Modulating the photon emission of the luminophore for boosting chemiluminescence (CL) response is very crucial for the construction of highly sensitive sensors via the introduction of functionalized materials. Herein, the integration of the emitter and coreactant accelerator into one entity is realized by simply assembling cucurbit[7]uril (CB[7]) on the surface of gold nanoparticles (AuNPs) through simple assembly via a Au-O bond. The loaded CB[7] on the AuNPs improves their catalytic capacity for the generation of hydroxyl radicals(•OH). Moreover, the host-guest recognition interaction between luminol and CB[7] enables the capture of luminol on AuNPs efficiently. Also, the intramolecular electron-transfer reaction between the luminol and •OH enables the CL response more effectively in the entity, which greatly boosts photon emission ca 100 folds compared with the individual luminol/H2O2. The host-guest recognition between luminol and CB[7] is revealed by Fourier transform infrared spectroscopy, electrochemical, and thermogravimetric characterization. Moreover, the proposed CL system is successfully used for the sensitive and selective determination of dopamine (DA) based on a synergistic quenching mechanism including the competition quenching and radical-scavenging effect from DA. The present amplified strategy by integrating recognized and amplified elements within one entity simplifies the sensing process and holds great potential for sensitive analysis based on the self-enhanced strategies.

Interaction between Phthalate Ester and Rice Plants: Novel Transformation Pathways and Metabolic-Network Perturbations.

Our understanding is limited concerning the interaction mechanism between widespread phthalate esters and staple crops, which have strong implications for human exposure. Therefore, this study was aimed at illuminating the transformation pathways of di-n-butyl phthalate (DnBP) in rice using an untargeted screening method. UPLC-QTOF-MS identified 16 intermediate transformation products formed through hydroxylation, hydrolysis, and oxidation in phase I metabolism and further by conjugation with amino acids, glutathione, and carbohydrates in phase II metabolism. Mono-2-hydroxy-n-butyl phthalate-l-aspartic acid (MHBP-asp) and mono-2-hydroxy-n-butyl phthalate-d-alanyl-ß-d-glucoside (MHBP-ala-glu) products were observed for the first time. The proteomic analysis demonstrated that DnBP upregulated the expression of rice proteins associated with transporter activity, antioxidant synthesis, and oxidative stress response and downregulated that of proteins involved in photosynthesis, photorespiration, chlorophyll binding, and mono-oxygenase activity. Molecular docking revealed that DnBP can affect protein molecular activity via pi-sigma, pi-alkyl, and pi-pi interactions or by forming carbon-hydrogen bonds. The metabolomic analysis showed that key metabolic pathways including citrate cycle, biosynthesis of aminoacyl-tRNA, and metabolism of amino acids, sphingolipids, carbohydrates, nucleotides, and glutathione were activated in rice plants exposed to DnBP and its primary metabolite mono-n-butyl phthalate (MnBP). Furthermore, exposure to 80 ng/mL MnBP significantly perturbed the metabolic profile and molecular function in plants, with downregulation of the levels of beta-alanine (0.56-fold), cytosine (0.48-fold), thymine (0.62-fold), uracil (0.48-fold), glucose (0.59-fold), and glucose-1-phosphate (0.33-fold), as well as upregulation of the levels of l-glutamic acid (2.97-fold), l-cystine (2.69-fold), and phytosphingosine (38.38-fold). Therefore, the degradation intermediates of DnBP pose a potentially risk to plant metabolism and raise concerns for crop safety related to plasticizer pollution.

DNA tetrahedron-mediated triplex molecular switch for extracellular pH monitoring.

This study aimed to construct a novel DNA triplex molecular switch modified with DNA tetrahedron (DTMS-DT) with sensitive response to extracellular pH using a DNA tetrahedron as the anchoring unit and DNA triplex as the response unit. The results showed that the DTMS-DT had desirable pH sensitivity, excellent reversibility, outstanding anti-interference ability, and good biocompatibility. Confocal laser scanning microscopy suggested that the DTMS-DT could not only be stably anchored on the cell membrane but also be employed to dynamically monitor the change in extracellular pH. Compared with the reported probes for extracellular pH monitoring, the designed DNA tetrahedron-mediated triplex molecular switch exhibited higher cell surface stability and brought the pH-responsive unit closer to the cell membrane surface, making the results more reliable. In general, developing the DNA tetrahedron-based DNA triplex molecular switch is helpful for understanding and illustrating the pH dependent cell behaviors and disease diagnostics.

New insight into phytometabolism and phytotoxicity mechanism of widespread plasticizer di (2-ethylhexyl) phthalate in rice plants.

Di-(2-ethylhexyl) phthalate (DEHP) as widely utilized plasticizer has aroused increasing concerns since its endocrine disrupting effects and continuous accumulation in biota. To date, the interaction mechanism between DEHP and rice plants has not been clearly illustrated at molecular level. Here, we investigated biological transformation and response of rice plants (Oryza sativa L.) to DEHP at realistic exposure concentrations. Nontargeted screening by UPLC-QTOF-MS was used to verify 21 transformation products derived from phase I metabolism (hydroxylation and hydrolysis) and phase II metabolism (conjugation with amino acids, glutathione, and carbohydrates) in rice. MEHHP-asp, MEHHP-tyr, MEHHP-ala, MECPP-tyr and MEOHP-tyr as the conjugation products with amino acids are observed for the first time. Transcriptomics analyses unraveled that DEHP exposure had strong negative effects on genes associated with antioxidative components synthesis, DNA binding, nucleotide excision repair, intracellular homeostasis, and anabolism. Untargeted metabolomics revealed that metabolic network reprogramming in rice roots was induced by DEHP, including nucleotide metabolism, carbohydrate metabolism, amino acid synthesis, lipid metabolism, synthesis of antioxidant component, organic acid metabolism and phenylpropanoid biosynthesis. The integrated analyses of interaction between differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) endorsed that metabolic network regulated by DEGs was significantly interfered by DEHP, resulting in cell dysfunction of roots and visible growth inhibition. Overall, these finding generated fresh perspective for crops security caused by plasticizer pollution and enhanced the public focus on dietary risk.

FRET cascade miRNA addition probe from non-crosstalk DNA photonic wire assisted with clustering algorithm for early diagnosis of acute myocardial infarction.

Early and accurate diagnosis of acute myocardial infarction (AMI) can significantly reduce patient mortality. A variety of miRNAs are found to dysregulate in AMI patients, but the up- or down-regulation of a specific miRNA may not be evident in the early stage, making it difficult to achieve accurate diagnosis. Here, proposing the design that DNA photonic wire (PW) with no spectral crosstalk would make an excellent template for miRNA conjoint analysis, we report the construction of a miRNA addition probe for the additive analysis of two up-regulated miRNAs (miR-133a and miR-208a) for early diagnosis of AMI in clinical serum samples. A three-dye non-crosstalk DNA PW is built to form the two-step fluorescence resonance energy transfer (FRET) cascade system, in which three paths can blocking the FRET cascade for separate or additive analysis of the two miRNAs. K-Means clustering algorithm is further utilized to classify the output signals of the miRNA addition probe, achieving a 100% accurate diagnosis of early AMI in both the training (n = 40) and validation (n = 19) cohorts of clinical serum samples.

Levels, Distribution and Health Risk Assessment of Organochlorine Pesticides in Agricultural Soils from the Pearl River Delta of China.

To reveal the pollution status of agricultural soils along with rapid urbanization and economic growth, a large regional survey of organochlorine pesticides (OCPs) in agricultural soils was conducted in the Pearl River Delta (PRD) of China. The results showed that the total residues of 23 OCPs were in the range of ND-946 ng/g dry weight. OCP residues showed distinct spatial distribution characteristics within the PRD. OCPs were mainly found in areas with high agricultural production and industrial activities. Higher OCP concentrations were observed in the top layer of soil, while the concentration decreases to marginal levels when the soil depth is greater than 50 cm. OCPs are mainly derived from historical use. Hexachlorocyclohexanes (HCHs) in the top soil of the study area are mainly from the use of lindane. Soil pH was negatively and significantly correlated with total OCP concentration. The human health risk assessment showed no health risk for children, while for adults, there is a non-carcinogenic risk, which needs to be noticed. Agricultural activities and industrial production have made the region a pollution hotspot and should arouse more stringent regulation to protect the environment and food safety.

Facile Uniaxial Electrospinning Strategy To Embed CsPbBr3 Nanocrystals with Enhanced Water/Thermal Stabilities for Reversible Fluorescence Switches.

All-inorganic halide perovskite nanocrystals with their fascinating optical properties have drawn increasing attention as promising nanoemitters. However, due to the intrinsic poor colloidal stability against the external environment, the practical applications are greatly limited. Herein, a facile and effective strategy for the in situ encapsulation of CsPbBr3 NCs into highly dense multichannel polyacrylonitrile (PAN) nanofibers via a uniaxial electrospinning strategy is presented. Such a facile uniaxial electrospinning strategy enables the in situ formation of CsPbBr3 NCs in PAN nanofibers without the introduction of stabilizers. Significantly, the obtained CsPbBr3 nanofibers not only display intense fluorescence with a high quantum yield (≈48%) but also present high stability when exposed to water and air owing to the peripheral protecting matrix of PAN. After immersing CsPbBr3@PAN nanofiber films in water for 100 days, the quantum yield of CsPbBr3@PAN nanofibers maintained 87.5% of the original value, which was much higher than that using CsPbBr3 NCs. Furthermore, based on the spectral overlap between the electrochromic material of ruthenium purple and fluorescence of CsPbBr3@PAN nanofiber films with excellent water stability, a reversible fluorescence switch is constructed with good fatigue resistance, suggesting their promising applications.

Characteristics and Health Risks of Phthalate Ester Contamination in Soil and Plants in Coastal Areas of South China.

Phthalate esters (PAEs) are widely used as plasticizers in industrial and commercial products, and are classified as endocrine-disrupting compounds. In this study, we investigated the contamination characteristics and health risks of PAEs in the soil-plant system in coastal areas of South China. PAEs were detected in soil and plant samples at all 37 sampling sites. The total concentration of the 15 PAEs in soil samples ranged from 0.445 to 4.437 mg/kg, and the mean concentration was 1.582 ± 0.937 mg/kg. The total concentration of the 15 PAEs in plant samples ranged from 2.176 to 30.276 mg/kg, and the mean concentration was 8.712 ± 5.840 mg/kg. Di(2-Ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the major PAEs compounds in all samples. The selected contaminants exhibited completely different spatial distributions within the study area. Notably, higher concentrations of PAEs were found in the coastal Guangdong Province of South China. The average noncarcinogenic risks of Σ6 PAEs were at acceptable levels via dietary and nondietary routes. However, the noncarcinogenic risks posed by DEHP and DBP at some sampling sites were relatively high. Furthermore, dietary and nondietary carcinogenic risks were very low for BBP, but carcinogenic risks posed by DEHP via diet. The results suggest that PAEs in the coastal soil-plant system in South China, through human risk assessment, will induce some adverse effects on human health, especially in children. This study provides an important basis for risk management of PAEs in agriculture, and safety in coastal areas of South China.

Catalytical feature of optical nanoprobes of boron nitride quantum dots in the presence of Cu2+ for the determination of dopamine.

Monitoring the concentration of dopamine (DA) is vital for preventing and diagnosing DA related diseases. In contrast to the traditional sensing methods for DA, in which direct or indirect effects on the optical probes are often recorded, a novel sensing concept is disclosed based on as a result of the in situ formation of polydopamine (PDA) originating from the synergetic effect between boron nitride quantum dots (BNQDs) and Cu2+. In the co-presence of BNQDs and Cu2+, DA was catalytically oxidized to PDA, accompanied by an obvious color change from colorless to brown. In contrast to previous reports, in which BNQDs have been employed as an optical probe, herein, the BNQDs not only acted as the optical energy donor, but also as the catalysts for the formation of PDA. The quenching efficiency resulting from the inner filter effect and the electron transfer between the BNQDs and PDA was directly proportional to the concentration of DA, ranging linearly from 2 to 80 µM with a limit of detection of 0.49 µM. The present system exhibited an outstanding selectivity for DA among other interfering coexisting biomolecules. Furthermore, the practical application of the proposed platform was verified by assaying DA in human plasma samples, and satisfactory recoveries ranging from 101.24% to 111.98% were obtained. With the satisfactory reliability, repeatability and stability, the proposed simple sensor showed significant potential for use in DA detection in other biomedical applications.

Atom-Anchoring Strategy with Metal-Organic Frameworks for Highly Efficient Solid-State Electrochemiluminescence.

A chemical fixation strategy originating from single-atom-anchoring with metal-organic frameworks as a carrying matrix was proposed for solid-state electrochemiluminescence (ECL). Herein, UiO-67(N) with the exposure of 2,2'-bipyridine (bpy) ligands could coordinate with Ru2+ to form a local structure of [Ru(bpy)3]2+ (Ru-UiO). The influence of the steric effect induced with different Ru sources was discussed. The as-obtained Ru-UiO exhibits high ECL intensity and outstanding stability in the presence of a coreactant at low concentrations. The proposed synthesis strategy may hold great potential for the synthesis of solid-state ECL materials and their further utilization in ECL analysis.

Universal Platform for Ratiometric Sensing Based on Catalytically Induced Inner-Filter Effect by Cu2.

Integrating two kinds of fluorescent probes in one system to develop a ratiometric sensing platform is of prime importance for achieving an accurate assay. Inspired by the efficient overlapped spectrum of 2-aminoterephthalic acid (PTA-NH2) and 2,3-diaminophenazine (DAP), a new sensitive ratiometric fluorescent sensor has been developed for Cu2+ on the basis of in situ converting o-phenylenediamine (OPD) into DAP through the catalysis of Cu2+. Here, the presence of Cu2+ induced the emission of DAP, which acted as an energy acceptor to inhibit the emission of PTA-NH2. This dual-emission reverse change ratiometric profile based on the inner-filter effect improved sensitivity and accuracy, and the highly sensitive determination of Cu2+ with a detection limit of 1.7 nmol·L-1 was obtained. The proposed sensing platform displayed the wide range of detection of Cu2+ from 5 to 200 nmol·L-1 by modulating the reaction time between Cu2+ and OPD. Moreover, based on the specific interaction between glutathione (GSH) and Cu2+, this fluorescent sensor showed high response toward GSH in a range of 0.5-80 µmol·L-1 with a detection limit of 0.16 µmol·L-1. The successful construction of this simple ratiometric sensing platform without the participation of enzymes provides a new route for the detection of small biological molecules that are closely related to human health.

In Situ Formed Catalytic Interface for Boosting Chemiluminescence.

Designing the catalytic interface that preferentially attracts reactants is highly desirable for amplifying chemiluminescence (CL) emission. Herein, to boost the generation of reactive oxygen species (ROS) from dissolved O2 molecule, flower-like cobalt hydroxide (f-Co(OH)2) based catalytic interface with hierarchical and porous architecture were in situ created in the coexistence of BSA and Co2+. Benefiting from the oxidase-like catalysis capability and the unique microstructure of f-Co(OH)2, ROS was efficiently produced. Meanwhile, the capping ligands of BSA endowed the interface with the capability of enriching functionality through the interaction between BSA and luminol. 100-fold CL enhancement was achieved using the as-prepared catalytic interface compared with the classical luminol-Co2+ or luminol-BSA system. Moreover, the proposed catalytic amplification mechanism could be extended to the different proteins such as lysozyme, protamine, thrombin, papain. Based on the quenching effect on CL, a sensitive sensing platform was constructed for the determination of ascorbic acid with satisfied results. Our finding provided a novel "all-in-one" route to design the catalytic interface for amplifying CL emission.

A General Method for Transition Metal Single Atoms Anchored on Honeycomb-Like Nitrogen-Doped Carbon Nanosheets.

Excavating and developing highly efficient and cost-effective nonnoble metal single-atom catalysts for electrocatalytic reactions is of paramount significance but still in its infancy. Herein, reported is a general NaCl template-assisted strategy for rationally designing and preparing a series of isolated transition metal single atoms (Fe/Co/Ni) anchored on honeycomb-like nitrogen-doped carbon matrix (M1 -HNC-T1 -T2 , M = Fe/Co/Ni, T1 = 500 °C, T2 = 850 °C). The resulting M1 -HNC-500-850 with M-N4 active sites exhibits superior capability for oxygen reduction reaction (ORR) with the half-wave potential order of Fe1 -HNC-500-850 > Co1 -HNC-500-850 > Ni1 -HNC-500-850, in which Fe1 -HNC-500-850 shows better performance than commercial Pt/C. Density functional theory calculations reveal a choice strategy that the strong p-d-coupled spatial charge separation results the Fe-N4 effectively merges active electrons for elevating d-band activity in a van-Hove singularity like character. This essentially generalizes an optimal electronic exchange-and-transfer (ExT) capability for boosting sluggish alkaline ORR activity. This work not only presents a universal strategy for preparing single-atom electrocatalyst to accelerate the kinetics of cathodic ORR but also provides an insight into the relationship between the electronic structure and the electrocatalytical activity.

Ratiometric sensing of alkaline phosphatase based on the catalytical activity from Mn-Fe layered double hydroxide nanosheets.

Two-dimensional (2D) Mn-Fe layered double hydroxide (LDH) nanosheets are firstly examined to mediate an O-phenylenediamine (OPD) based fluorescent switch in the presence of ascorbic acid (AA). On one hand, Mn-Fe LDH mimicked the functions of oxidase to catalyze the oxidation of OPD to OPDox, emitting fluorescence at 565 nm. On the other hand, Mn-Fe LDH acts as a superior catalyst for the reaction between AA and OPD to generate 3-(1,2-dihydroxyethyl)furo[3,4-b]quinoxalin-1(3H)-one (N-heterocyclic compound) with an emergence of the maximum emission at 425 nm (ca. 6 fold). The presence of AA not only induces the enhanced emission at 425 nm from the N-heterocyclic compound, but also leads to decreased fluorescence at 565 nm due to the decomposition of Mn-Fe LDH nanosheets. On the basis of the reversed fluorescence response at 425 and 565 nm, ratiometric fluorescence sensing methods (ΔF425 nm/ΔF565 nm) are developed for the determination of AA. With the assistance of alkaline phosphatase (ALP), the activity of ALP can be monitored using the ratiometric platform based on the hydrolyzing ascorbic acid 2-phosphate to yield AA with the detection limit of 0.16 mU mL-1. Different from the traditional ratiometric sensing platform, where two fluorescent probes are often introduced, the present ratiometric system derived from one signal precursor holds great potential in developing a facile platform and broadens the application of 2D nanomaterials in the field of biology.

Glutathione Regulated Inner Filter Effect of MnO2 Nanosheets on Boron Nitride Quantum Dots for Sensitive Assay.

Glutathione (GSH) can help the body maintain the function of the normal immune system and its level change is associated with a variety of diseases. To achieve the ultrasensitive assay of GSH, a "switch on" nanosensor is designed on the basis of GSH regulating the inner filter effect (IFE) of MnO2 nanosheets (MnO2 NS) on boron nitride quantum dots (BNQDs). Here, the fluorescence of BNQDs is quenched efficiently in the presence of redoxable MnO2 NS because of the superior light absorption capability; however, the introduction of GSH can trigger the decomposition of MnO2 to Mn2+ and weaken the IFE, causing the partial fluorescence recovery. The recovered fluorescence is dependent on the concentration of GSH. Under the optimal conditions, this sensing platform shows the response to GSH in the range of 0.5-250 µM with the detection limit of 160 nM. On the basis of the GSH activated reduction of MnO2 NS, the MnO2 NS/BNQDs nanoprobes exhibit good selectivity to GSH. The practical application of the proposed system is demonstrated by detecting the GSH in human plasma samples with satisfying results.

Point-of-Care Diagnoses: Flexible Patterning Technique for Self-Powered Wearable Sensors.

This paper demonstrated the fabrication of a facile, low-cost, and self-powered platform for point-of-care fitness level and athletic performance monitoring sensor using electrochemical lithography method and its application in body fluid sensing. Flexible Au/prussian blue electrode was employed as the indicating electrode, where the color change was an indication of fitness level and athletic performance. A piece of Al foil, Au/multiwalled carbon nanotubes (MWCNTs)-glucose dehydrogenase, and Au/polymethylene blue-MWCNTs-lactic dehydrogenase electrodes were used for the detection of ionic strength, glucose, and lactic acid in sweat, respectively, which allows the sensor to work without any extra instrumentation and the output signal can be recognized by the naked eyes. The advantages of these sensors are (1) self-powered; (2) readily applicable to the detection of any electroactive substance by an electrochromic material; (3) easy to fabricate via two steps of EDP; and (4) point-of-care. By assembling the energy and sensing components together through a transparent adhesive tape, the proposed self-powered wearable biosensor exhibits superior performances, indicating its broad applied prospect in the point-of-care diagnoses.

Co3 O4 /Fe0.33 Co0.66 P Interface Nanowire for Enhancing Water Oxidation Catalysis at High Current Density.

Designing well-defined nanointerfaces is of prime importance to enhance the activity of nanoelectrocatalysts for different catalytic reactions. However, studies on non-noble-metal-interface electrocatalysts with extremely high activity and superior stability at high current density still remains a great challenge. Herein, a class of Co3 O4 /Fe0.33 Co0.66 P interface nanowires is rationally designed for boosting oxygen evolution reaction (OER) catalysis at high current density by partial chemical etching of Co(CO3 )0.5 (OH)·0.11H2 O (Co-CHH) nanowires with Fe(CN)6 3- , followed by low-temperature phosphorization treatment. The resulting Co3 O4 /Fe0.33 Co0.66 P interface nanowires exhibit very high OER catalytic performance with an overpotential of only 215 mV at a current density of 50 mA cm-2 and a Tafel slope of 59.8 mV dec-1 in 1.0 m KOH. In particular, Co3 O4 /Fe0.33 Co0.66 P exhibits an obvious advantage in enhancing oxygen evolution at high current density by showing an overpotential of merely 291 mV at 800 mA cm-2 , much lower than that of RuO2 (446 mV). Co3 O4 /Fe0.33 Co0.66 P is remarkably stable for the OER with negligible current loss under overpotentials of 200 and 240 mV for 150 h. Theoretical calculations reveal that Co3 O4 /Fe0.33 Co0.66 P is more favorable for the OER since the electrochemical catalytic oxygen evolution barrier is optimally lowered by the active Co- and O-sites from the Co3 O4 /Fe0.33 Co0.66 P interface.

Chemiluminescence of CsPbBr3 Perovskite Nanocrystal on the Hexane/Water Interface.

All-inorganic halide perovskite CsPbBr3 nanocrystals (NCs) have attracted more attention in recent years due to the unique optical feature. To date, most of the research was mainly focused on the photoluminescence (PL) and electrochemiluminescence (ECL) of the perovskite NCs. In this work, the strong chemiluminescence (CL) emission of CsPbBr3 NCs was observed for the first time on the hexane/water interface with the assistance of ammonium persulfate-(NH4)2S2O8 as coreactant. Different coreactants were investigated to demonstrate the effect on the CL behavior and it was found that CL intensity achieved the maximum in the presence of (NH4)2S2O8. In this system, electron transfer took place on the surface of the CsPbBr3 NCs, and the excited CsPbBr3 NCs was originated from the direct chemical oxidation of (NH4)2S2O8. The CL spectrum of CsPbBr3 NCs was also collected and was consistent with their PL and ECL spectra, indicating that CsPbBr3 NCs played a role of luminophor during the CL process. The discovery of monochromatic CL of highly crystallized CsPbBr3 NCs not only extends the applications of halide perovskite materials in the analytical field but also provides a new route for the exploration of the physical chemistry properties.

Boron Nitride Quantum Dots as Efficient Coreactant for Enhanced Electrochemiluminescence of Ruthenium(II) Tris(2,2'-bipyridyl).

In the present work, an enhanced and stable anodic electrochemiluminescence (ECL) was observed from a suspension of boron nitride quantum dots (BNQDs) and Ru(bpy)32+, which had a 400-fold enhancement compared with individual Ru(bpy)32+. Interestingly, different from the previous research on BNQDs as a type of optical probe, BNQDs were demonstrated as an efficient coreactant of Ru(bpy)32+-based ECL for the first time and confirmed by collecting the ECL spectra. The amino-bearing groups and the electrocatalytic effect of the BNQDs endowed them as potential coreactants for ECL of Ru(bpy)32+, and the possible mechanism of the electrode surface reaction was discussed. Several factors including electrode material, the pH of the buffer solution, and the amount of BNQDs were investigated and also further confirmed the role of the BNQDs in the proposed Ru(bpy)32+/BNQDs system. On the basis of the quenching effect between the excited state of Ru(bpy)32+ and the oxidation form of DA in the ECL system of Ru(bpy)32+/BNQDs, the ECL sensing platform for DA was successfully established. The proposed ECL system with the outstanding ECL efficiency may hold great potential in the bioanlysis because of the biocompatibility and good stability of BNQDs.