RESUMEN
Photoelectric devices are extensively applied in optical logic systems, light communication, optical imaging, and so on. However, traditional photoelectric devices can only generate unidirectional photocurrent, which hinders the simplification and multifunctionality of devices. Recently, it has become a new research focus to achieve controllable reversal of the output photocurrent direction (bipolar current) in a photoelectric system. Considering that the device with bipolar current adds a reverse current operating state compared to traditional devices, the former is more suitable for developing new multifunctional photoelectric devices. Due to the existence of electrolytes, photoelectrochemical (PEC) systems contain chemical processes such as ion diffusion and migration and electrochemical reactions, which are unable to occur in solid-state transistor devices, and the effect of electrolyte pH on the performance of PEC systems is usually ignored. We prepared a MnPS3-based PEC-type photodetector and reversed photocurrents by adjusting the pH of electrolytes, i.e., the electrolyte-controlled photoelectrochemical photocurrent switching (PEPS) effect. We clarified the effect of pH values on the direction of photocurrent from the perspectives of electrolyte energy level rearrangement splitting and the kinetic theory of the semiconductor electrode. This work not only contributes to a deeper understanding of carrier transport in PEC processes but also inspires the development of advanced multifunctional photoelectric devices.
RESUMEN
As an important economic sector, logistics is becoming more important, if not crucial, in economic growth. In our nation, the logistics industry is booming, and it's just getting better. However, in addition to focusing on the positive aspects of our country's logistics industry's development, we should also analyze and address the negative aspects of our country's logistics industry's development. The overall logistics pattern has not yet been formed, and there is an urgent need for systematic construction. The regional development is extremely unbalanced. By comparing the logistics performance indices of various Belt and Road countries, this research aims to examine the major elements influencing overall logistics performance. Second, we introduce the Moran index to explore the geographical association of the subdivision indicators of the logistics performance index using the spatial econometric model. The bootstrap DEA analysis method examines and ranks the countries' logistics performance indexes, determines our country's advantages and disadvantages in comparison to other Belt and Road countries, and executes specific improvement strategies that will enhance logistics and boost the overall growth of our country's logistics sector.
Asunto(s)
Industrias , China , GeografíaRESUMEN
This work reports an efficient [(C6)2Ir(dppz)]+PF6- (C6 = coumarin 6 and dppz = dipyridophenazine)-sensitized NiO photocathode and its application in photoelectrochemical (PEC) bioanalysis field for the first time. This dye-sensitized NiO photocathode was found to exhibit a markedly enhanced cathodic photocurrent. A sensitive cathodic PEC platform was proposed integrating the as-prepared photocathode with enzyme-free cascaded amplification strategies of the catalytic hairpin assembly (CHA) and the hybridization chain reaction (HCR) for DNA methyltransferase (MTase) assay. A hairpin DNA(HDam) with specific recognition site of Dam MTase in its stem was designed. The site of HDam was methylated in the presence of Dam MTase and then cut by endonuclease DpnI. The released loop fragment, as an initiator, triggered the CHA circuit and the follow-up HCR circuit, resulting in long dsDNA concatemers on the ITO electrode. Numerous [(C6)2Ir(dppz)]+PF6- were intercalated into dsDNA, and highly efficient signal amplification was realized. Benefiting from the superior iridium(III) complex-sensitized NiO photocathode and effective amplification strategy, a detection limit of 0.0028 U/mL for the determination of Dam MTase was achieved. Moreover, this work further demonstrated that these proposed tactics could be applied to screen Dam MTase activity inhibitors.
Asunto(s)
Técnicas Biosensibles , Iridio , Técnicas Biosensibles/métodos , ADN , Electrodos , Hibridación de Ácido NucleicoRESUMEN
In this study, a coumarin-appended cyclometalated iridium (III) complex was prepared and demonstrated to be an efficient photoelectrochemical (PEC) active species with stable and reproducible cathodic photocurrent illuminated by visible light. A gold nanoparticles (AuNPs)-based PEC probe was assembled using the as-prepared iridium (III) complex as signal reporter. Integrating aptamer/protein proximity binding-triggered strand displacement and catalytic hairpin assembly (CHA) amplification strategy, an enzyme-free and sensitive PEC assay was developed. Benefiting from superior photon-to-current conversion character of the iridium (III) complex and effective amplification strategy, the proposed assay exhibited enhanced sensitivity for thrombin detection with a detection limit of 23â¯fM. It also showed a high specificity in serum samples. This study further demonstrated that cyclometalated iridium (III) complexes could be adopted as favorable photoactive material for bioanalysis by improving their ability of absorbance in the visible region.