Influence of local governments on the greening of the manufacturing sector: A perspective on environmental governance objectives.

The green development of manufacturing industries is significantly impacted by local governments. In this study, we focus on assessing the environmental governance effectiveness by examining the tasks assigned by the central government to each province under the Comprehensive Work Program for Energy Conservation and Emission Reduction. By utilizing panel data from 30 provinces and cities in China from 2011 to 2020, we employ the super-efficient SBM model to evaluate China's manufacturing industry's green total factor productivity. Through various models, including the double-fixed effect and the mediation effect, we investigate the influence of environmental governance targets on the green total factor productivity of the manufacturing industry. Our findings reveal a U-shaped relationship between the environmental governance target and the green total factor productivity of the manufacturing industry. When the pressure of environmental governance targets is below a certain critical value, the green total factor productivity decreases as the target pressure increases. However, once the target pressure surpasses this critical value, the green total factor productivity experiences a positive correlation with the target pressure. Further analysis demonstrates that this U-shaped relationship is observed in regions with low and medium marketization, while regions with high marketization remain unaffected. Moreover, the impact of environmental governance target pressure on green total factor productivity in manufacturing is facilitated by the promotion of green innovation. Furthermore, the relationship between environmental governance target pressure and green total factor productivity in manufacturing is moderated by local government fiscal expenditures. In regions where fiscal expenditures are higher, the influence of environmental governance target pressure on green total factor productivity in manufacturing is more pronounced.

Multidimensional performance assessment, government competition and ecological welfare performance.

Improving the efficiency of converting natural resources into social benefits is an important issue for sustainable development in today's world. Based on this background this paper applies the super-efficient SBM model with non-expected output to measure the ecological welfare performance (EWP) of Chinese provinces from 2005-2019, and explores the relationship between government competition and EWP under different assessment systems. The research results show that government competition under economic performance assessment is self-interested and short-sighted, which can negatively affect ecological welfare performance in the current period as well as in the next four years. In contrast, government competition under the environmental assessment system promotes EWP in both the current and long term, balancing short-term and long-term benefits. The results of the spatial GMM found that government competition under economic performance appraisal can deteriorate EWP in local as well as surrounding areas, but government competition under the environmental assessment system can achieve an increase in local ecological welfare performance and the spillover effect is not significant. To alleviate the limitations of a single appraisal system, this paper incorporates both economic and ecological appraisals into the multidimensional appraisal system. When the weights of both are between 1:9 and 3:7, the government competition under multidimensional performance appraisal can promote both current and longer-term EWP, and achieve its own ecological welfare performance without affecting the surrounding areas.

Research on the evolution and driving factors of digitalization of energy in China-A new perspective based on coupling coordination.

The world is experiencing the tide of digital transformation. Promoting the digitalization of energy is an important measure to realize energy sustainability. The digitalization of energy is a product of the coupled and coordinated development of the energy industry and the digital economy. This paper takes 30 provinces in China from 2011 to 2020 as research objects. The Entropy Weight Method is used to measure the development level of China's energy industry and digital economy, and the Coupling Coordination Degree Model is used to measure the digitalization of energy (DE). Then, the evolution characteristics and driving factors of China's DE are studied by using Grey Prediction Model, Kernel Density Analysis Method and Geodetector Model. The conclusions are mainly as follows: (1) Though the development level of energy industry and digital economy in China are both growing over time, there are distinct features in their spatial distribution. (2) The DE is in a disorderly state as a whole, but it will be upgraded to the stage of barely coordinated during China's 14th Five-Year Plan period (2021-2025). From the evolutionary process, the distribution pattern and trend changes of DE are characterized by obvious polarization distribution and increasing absolute differences, and this feature is more obvious in the central and western regions. (3) Government support, FDI, and pollution governance have an increasing impact on DE, but this impact varies considerably between the east and central-west regions. Therefore, this paper suggests that local governments should formulate policies to promote the DE according to local conditions. The central government should focus on accelerating the construction of the "East Digital West Computing" project and the development of the energy Internet to solve the problem of uneven regional development.

Elucidating Electrocatalytic Oxygen Reduction Kinetics via Intermediates by Time-Dependent Electrochemiluminescence.

Facile evaluation of oxygen reduction reaction (ORR) kinetics for electrocatalysts is critical for sustainable fuel-cell development and industrial H2 O2 production. Despite great success in ORR studies using mainstream strategies, such as the membrane electrode assembly, rotation electrodes, and advanced surface-sensitive spectroscopy, the time and spatial distribution of reactive oxygen species (ROS) intermediates in the diffusion layer remain unknown. Using time-dependent electrochemiluminescence (Td-ECL), we report an intermediate-oriented method for ORR kinetics analysis. Owing to multiple ultrasensitive stoichiometric reactions between ROS and the ECL emitter, except for electron transfer numbers and rate constants, the potential-dependent time and spatial distribution of ROS were successfully obtained for the first time. Such exclusively uncovered information would guide the development of electrocatalysts for fuel cells and H2 O2 production with maximized activity and durability.

Ultrafast Condensation of Carbon Nitride on Electrodes with Exceptional Boosted Photocurrent and Electrochemiluminescence.

Semiconducting polymeric carbon nitride (CN) has drawn wide attention ranging from photocatalysis to more recent biosensing owing to unique defect-tolerated optoelectronic properties and being metal-free, cheap, and highly stable. However, at the core of electrical-optical interconversion, the preparation of the CN photoelectrode is still challenging. Now, the growth of CN on electrodes is achieved simply by microwave-assisted condensation in seconds. The ultrafast heating not only addressed the thermodynamic contradiction of precursor volatilization during polymerization but also led to strongly adhesive CN layer on electrodes with gradient carbon-rich texture, greatly accelerating the electron-hole separation and mobility. Consequently, the CN photoelectrode exhibited a remarkable photocurrent and a record cathodic efficiency of electrochemiluminescence up to 7 times that of benchmark Ru(bpy)3 Cl2 in aqueous solution.

Exfoliation and Sensitization of 2D Carbon Nitride for Photoelectrochemical Biosensing under Red Light.

Two-dimensional carbon nitride (CN) has drawn increasing attention as a conjugated metal-free polymer for photoelectrochemical (PEC) biosensing. However, CN only absorbs ultraviolet and very limited visible light (λ<460 nm), which poses potential risks for biomolecules and also cannot pass through tissue for in vivo detection. Herein, simultaneous exfoliation and functionalization of CN nanosheets (CNNS) with copper phthalocyanine (TsCuPc) simply by mechanical milling, thanks to the delicate π-π interaction between them, is reported. Moreover, due to energy-level matching, an effective donor-acceptor (D-A) interaction with much-improved photocurrent under irradiation with red light (λ>630 nm) was observed for the as-prepared CNNS-TsCuPc. As an example, dopamine in blood was detected by using red light by a CNNS-TsCuPc photoelectrode with uncompromised linear range and detection limit, as well high selectivity. As one of the few successful demonstrations of red-light-responsive PEC sensing systems, this work takes a first step toward future in vivo applications by enriching the optoelectronic properties of CN with task-specific antenna molecules via D-A interaction.

Metal-Free All-Carbon Nanohybrid for Ultrasensitive Photoelectrochemical Immunosensing of alpha-Fetoprotein.

C60 can accept up to six electrons reversibly and show exceptional light absorption over the entire UV-vis spectrum, making it a potential photoactive probe for photoelectrochemical (PEC) bioassay. However, few successful works have been reported to apply fullerenes in PEC biosensing, partially because of the low electronic conductivity and poor interfacial interactions with targeted biomolecules. Herein, we report the addressing of these two obstacles by coupling high conductive graphite flake (Gr), graphene oxide (GO) with sufficient oxygen-containing functional groups, and an alkylated C60 (AC60) into a metal-free all-carbon nanohybrid (AC60-Gr-GO) via harnessing delicate noncovalent interactions among them through a facile mechanical grinding. It was revealed that the as-obtained AC60-Gr-GO nanohybrid not only showed conspicuous enhancement of photocurrent up to 35 times but also offered rich anchors for bioconjugation. With detection of alpha-fetoprotein as an example, the AC60-Gr-GO based PEC immunosensor demonstrated a broad linear detection range (1 pg·mL-1 to 100 ng·mL-1) and a detection limit as low as 0.54 pg·mL-1, superior/competitive to PEC immunosensors for AFP in previous reports. By a proper reinforcement in conductivity and biointerface engineering, this work may provide a new way to use fullerenes as photoactive materials in more general PEC biosensing.

Coupled Fluorometer-Potentiostat System and Metal-Free Monochromatic Luminophores for High-Resolution Wavelength-Resolved Electrochemiluminescent Multiplex Bioassay.

The sensitive simultaneous detection of multiple biomarkers is critical for the early diagnosis of diseases. Electrochemiluminescence (ECL) offers outstanding advantages, e.g., low background, over other optical sensing techniques. However, multiplexed ECL bioassay is hindered not only by the lack of generally available ECL spectrometers but also by the limited number of biocompatible monochromatic ECL luminophores for decades. Herein, we report addressing these issues by re-examination of the recent tabletop spectrofluorometer coupled potentiostat as a high-resolution ECL spectrum acquisition system and using carbon nitrides as monochromatic luminophores. A wavelength-resolved multiplexing ECL biosensor is demonstrated to simultaneously detect CA19-9 and mesothelin, two pancreatic cancer biomarkers, at a single-electrode interface. This work could initiate new opportunities for more general multiplex ECL biosensors with competitive performances.

Competitive Multiple-Mechanism-Driven Electrochemiluminescent Detection of 8-Hydroxy-2'-deoxyguanosine.

Natural selection over billions of years has developed highly effective in vivo signal transduction that is often governed by a series of competitive multiple mechanisms. Several artificial signal transduction pathways have inspired numerous biosensing systems, but most of these are driven by a single mechanism. Herein we describe a multiple-mechanism-driven electrochemiluminescent (ECL) biosensor that utilizes competitive catalytic and steric hindrance effects by assembling hemin/G-quadruplex on carbon nitride nanosheets. Taking the detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) as example, the dynamic ranges of the detectable concentrations from the different mechanisms were integrated into a single sensor interface. Moreover, the detection sensitivity was more precisely controlled by the competition between the two mechanisms and inherently boosted compared with that of single-mechanism-driven detection. Going beyond the conventional single-mechanism-driven biosensing, the elaborate biomimetic coupling of multiple mechanisms in a single interface may open a new approach for future multiplexed biosensing.

Highly Sensitive and Quality Self-Testable Electrochemiluminescence Assay of DNA Methyltransferase Activity Using Multifunctional Sandwich-Assembled Carbon Nitride Nanosheets.

DNA methylation catalyzed by methylase plays a key role in many biological activities. However, developing a highly sensitive, simple, and reliable way for evaluation of DNA methyltransferase (MTase) activity is still a challenge. Here, we report a sandwich-assembled electrochemiluminescence (ECL) biosensor using multifunctional carbon nitride nanosheets (CNNS) to evaluate the Dam MTase activity. The CNNS could not only be used as an excellent substrate to conjugate a large amount of hairpin probe DNA to improve the sensitivity but also be utilized as an internal reliability checker and an analyte reporter in the bottom and top layers of the biosensor, respectively. Such a unique sandwich configuration of CNNS well coupled the advantages of ECL luminophor that were generally assembled in the bottom or top layer in a conventional manner. As a result, the biosensor exhibited an ultralow detection limit down to 0.043 U/mL and a linear range between 0.05 and 80 U/mL, superior to the MTase activity assay in most previous reports. We highlighted the great potential of emerging CNNS luminophor in developing highly sensitive and smart quality self-testable ECL sensing systems using a sandwiched configuration for early disease diagnosis, treatment, and management.

Simultaneous Noncovalent Modification and Exfoliation of 2D Carbon Nitride for Enhanced Electrochemiluminescent Biosensing.

As an emerging nitrogen-rich 2D carbon material, graphitic carbon nitride (CN) has drawn much attention for applications ranging from photo-/electrocatalysts to biosensors. Interfacial modification of CN is fundamentally vital but is still in its infancy and remains challenging due to the low reactivity of CN. Here we report that, in conjunction with a π-π stacking interaction, bulk CN could be simultaneously exfoliated via facile mechanical grinding. The obtained CN nanosheets (m-CNNS) not only retained the pristine optoelectronic properties of bulk CN but also enriched a friendly interface for further coupling biomolecules with advanced properties, overcoming the deficiencies of CN in surface science. The m-CNNS were further covalently linked to a DNA probe, and the resultant electrochemiluminescent biosensor for the target DNA exhibited much enhanced sensitivity with respect to that obtained by direct physical absorption of the DNA probe on unmodified CNNS. This noncovalent exfoliation and interfacial modification should greatly expand the scope of potential applications of CN in areas such as biosensing and should also be applicable to other 2D materials in interface modulation.

Chemically Modulated Carbon Nitride Nanosheets for Highly Selective Electrochemiluminescent Detection of Multiple Metal-ions.

Chemical structures of two-dimensional (2D) nanosheet can effectively control the properties thus guiding their applications. Herein, we demonstrate that carbon nitride nanosheets (CNNS) with tunable chemical structures can be obtained by exfoliating facile accessible bulk carbon nitride (CN) of different polymerization degree. Interestingly, the electrochemiluminescence (ECL) properties of as-prepared CNNS were significantly modulated. As a result, unusual changes for different CNNS in quenching of ECL because of inner filter effect/electron transfer and enhancement of ECL owing to catalytic effect were observed by adding different metal ions. On the basis of this, by using various CNNS, highly selective ECL sensors for rapid detecting multiple metal-ions such as Cu(2+), Ni(2+), and Cd(2+) were successfully developed without any labeling and masking reagents. Multiple competitive mechanisms were further revealed to account for such enhanced selectivity in the proposed ECL sensors. The strategy of preparing CNNS with tunable chemical structures that facilely modulated the optical properties would open a vista to explore 2D carbon-rich materials for developing a wide range of applications such as sensors with enhanced performances.

Highly sensitive fluorescence assay of DNA methyltransferase activity by methylation-sensitive cleavage-based primer generation exponential isothermal amplification-induced G-quadruplex formation.

Site-specific identification of DNA methylation and assay of MTase activity are imperative for determining specific cancer types, provide insights into the mechanism of gene repression, and develop novel drugs to treat methylation-related diseases. Herein, we developed a highly sensitive fluorescence assay of DNA methyltransferase by methylation-sensitive cleavage-based primer generation exponential isothermal amplification (PG-EXPA) coupled with supramolecular fluorescent Zinc(II)-protoporphyrin IX (ZnPPIX)/G-quadruplex. In the presence of DNA adenine methylation (Dam) MTase, the methylation-responsive sequence of hairpin probe is methylated and cleaved by the methylation-sensitive restriction endonuclease Dpn I. The cleaved hairpin probe then functions as a signal primer to initiate the exponential isothermal amplification reaction (EXPAR) by hybridizing with a unimolecular DNA containing three functional domains as the amplification template, producing a large number of G-quadruplex nanostructures by utilizing polymerases and nicking enzymes as mechanical activators. The G-quadruplex nanostructures act as host for ZnPPIX that lead to supramolecular complexes ZnPPIX/G-quadruplex, which provides optical labels for amplified fluorescence detection of Dam MTase. While in the absence of Dam MTase, neither methylation/cleavage nor PG-EXPA reaction can be initiated and no fluorescence signal is observed. The proposed method exhibits a wide dynamic range from 0.0002 to 20U/mL and an extremely low detection limit of 8.6×10(-5)U/mL, which is superior to most conventional approaches for the MTase assay. Owing to the specific site recognition of MTase toward its substrate, the proposed sensing system was able to readily discriminate Dam MTase from other MTase such as M.SssI and even detect the target in a complex biological matrix. Furthermore, the application of the proposed sensing strategy for screening Dam MTase inhibitors was also demonstrated with satisfactory results. This novel method not only provides a promising platform for monitoring activity and inhibition of DNA MTases, but also shows great potentials in biological process researches, drugs discovery and clinical diagnostics.

A DNA nanomachine based on rolling circle amplification-bridged two-stage exonuclease III-assisted recycling strategy for label-free multi-amplified biosensing of nucleic acid.

An autonomous DNA nanomachine based on rolling circle amplification (RCA)-bridged two-stage exonuclease III (Exo III)-induced recycling amplification (Exo III-RCA-Exo III) was developed for label-free and highly sensitive homogeneous multi-amplified detection of DNA combined with sensitive fluorescence detection technique. According to the configuration, the analysis of DNA is accomplished by recognizing the target to a unlabeled molecular beacon (UMB) that integrates target-binding and signal transducer within one multifunctional design, followed by the target-binding of UMB in duplex DNA removed stepwise by Exo III accompanied by the releasing of target DNA for the successive hybridization and cleavage process and autonomous generation of the primer that initiate RCA process with a rational designed padlock DNA. The RCA products containing thousands of repeated catalytic sequences catalytically hybridize with a hairpin reporter probe that includes a "caged" inactive G-quadruplex sequence (HGP) and were then detected by Exo III-assisted recycling amplification, liberating the active G-quadruplex and generating remarkable ZnPPIX/G-quadruplex fluorescence signals with the help of zinc(II)-protoporphyrin IX (ZnPPIX). The proposed strategy showed a wide dynamic range over 7 orders of magnitude with a low limit of detection of 0.51 aM. In addition, this designed protocol can discriminate mismatched DNA from perfectly matched target DNA, and holds a great potential for early diagnosis in gene-related diseases.

Ultrasensitive fluorescence detection of nucleic acids using exonuclease III-induced cascade two-stage isothermal amplification-mediated zinc (II)-protoporphyrin IX/G-quadruplex supramolecular fluorescent nanotags.

A cascadic sensing system was developed for detection of DNA target at ultralow concentration by a combination of magnetic nanoparticles (MNPs) and exonuclease III (Exo III)-induced cascade two-stage isothermal amplification in the study. An ingeniously designed capture hairpin probe (CHP) that integrates target-binding and signal transduction sequences within one multifunctional design was assembled on MNPs. Upon sensing of the analyte nucleic acid, the hairpin probe on MNPs could be opened and stepwise removed by Exo III accompanied by the releasing of target DNA for the successive hybridization and cleavage process and the generation of bare signal transduction sequences of CHP as a new trigger for next circular reaction. The new DNA triggers initiate hybridizing with hairpin DNA probe that contains a partially "caged" G-quadruplex sequence (GHP), forming a duplex structure and liberating the active G-quadruplex structure. Then, Exo III digests the resulting duplex domain, leading to the recycling of new DNA trigger and simultaneously generating numerous ZnPPIX/G-quadruplex supramolecular complexes with the help of the zinc (II)-protoporphyrin IX (ZnPPIX), as an optical label for amplified fluorescence sensing event. Finally, numerous liberated cascade ZnPPIX/G-quadruplex supramolecular complexes give a remarkable fluorescence response. Because of two-stage autocatalytic recycling amplification and the specifically catalyzed formation of ZnPPIX/G-quadruplex supramolecular complexes, this newly designed protocol provides a high sensitivity with a detection limit of 0.75 fM, can discriminate mismatched DNA from perfectly matched target DNA, and gives low matrix effect due to using MNPs as the separation and amplification elements in the real samples. Therefore, it holds great potential for early diagnosis in gene-related diseases.

A label-free fluorescence assay for thrombin based on aptamer exonuclease protection and exonuclease III-assisted recycling amplification-responsive cascade zinc(II)-protoporphyrin IX/G-quadruplex supramolecular fluorescent labels.

A simple, label-free and sensitive fluorescence protein assay has been developed on the basis of aptamer exonuclease protection and exonuclease III (Exo III)-assisted recycling amplification-responsive cascade ZnPPIX/G-quadruplex supramolecular fluorescent labels. In the sensing system, a special aptamer probe containing the aptamer sequence at the 3'-terminus and the DNAzyme sequence at the 5'-terminus was applied, which has the capacity to recognize a protein target with high affinity and specificity. Exonuclease I (Exo I) can efficiently catalyze the degradation of free single stranded DNA probes in the 3' to 5' direction. In the presence of the target protein, the strong binding between the target protein and its aptamer can protect aptamer probes from degradation. Subsequently, the protected aptamer probes act as catalysators to trigger hybridization with the hairpin DNA probe that contains a partially "caged" G-quadruplex sequence. Upon interaction with the protected aptamer probes, the hairpin opens to yield the active G-quadruplex structure. In the presence of exonuclease III (Exo III), Exo III-assisted recycling amplification occurs generating numerous G-quadruplex supramolecular structures. The zinc(ii)-protoporphyrin IX (ZnPPIX) fluorophore binds to the G-quadruplexes and this results in the enhanced fluorescence of the fluorophore. The resulting fluorescence of the ZnPPIX/G-quadruplex provides the readout signal for the sensing event. Thrombin is used as the model analyte in the current proof-of-concept. The developed method was demonstrated to have very high sensitivity for the detection of proteins with a limit of detection of 0.2 pM without using washes or separations. In addition, this new method for protein detection is simple and inherits all the advantages of aptamers. The mechanism, moreover, may be generalized and used for other forms of protein analysis.