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Engineering 3D dual-functional electrodes with non-noble metals toward efficient overall water electrolysis is significantly important but challenging for the renewable chemical fuels. Here, vanadium doped Ni 3 S 2 nanosheets array decorated on carbon fiber cloth (V-Ni 3 S 2 /CC) is successfully constructed as 3D dual-functional electrodes for efficient overall water splitting. The specific nanosheet array electrode provides structural benefits of high contact area, abundant accessible catalytic sites, shortened and accelerated charge transfer, and improved electrolyte penetration. Moreover, the vanadium dopants have a positive effect on the catalysis process, contributing to the improved intrinsic activity and accelerated catalysis reaction kinetics of Ni 3 S 2 catalyst. Reasonably, the developed V-Ni 3 S 2 /CC electrodes exhibit robust water splitting performances, with small overpotential of 180 mV for oxygen evolution reaction and 81 mV for hydrogen evolution reaction at 10 mA cm−2. In a V-Ni 3 S 2 /CC dual-electrodes constructed electrolyzer system, an ultralow cell potential of 1.49 V is achieved for a stable catalytic current of 10 mA cm−2, outperforming most of the reported non-noble metals based dual-functional electrocatalysts. Unlabelled Image • Vanadium doped Ni 3 S 2 nanosheet array for overall water splitting. • Nanosheet array supplies structure benefits for improved electrocatalysis. • V dopants improve both intrinsic activity and reaction kinetics. • Excellent HER, OER, and overall water splitting activities are achieved. [ABSTRACT FROM AUTHOR]

Despite the intensive focuses on developing Prussian blue analogues (PBAs) derived catalysts, the direct utilization of PBAs for electrochemical water splitting to produce oxygen and especially hydrogen sources has rarely been reported, because of lacking effective strategies to improve the active site density and electrical transport of PBAs. Herein, we resolve such challenges by constructing the cubic NiCo-PBA bricks assembled 2D nanowalls on Ni foam (NF) through a Ni(OH) 2 nanosheet confined template technique. A great amount of sites are generated along the borders of brick subunits, and the 2D feature supplies downscaled charge diffusion path and high accessible surface area. Therefore, NiCo-PBA/NF exhibits impressive water electrolysis activities, with low overpotentials of 200 and 62 mV at 10 mA cm−2 for oxygen evolution reaction and hydrogen evolution reaction, respectively. Moreover, the NiCo-PBA/NF coupled two-electrode system achieves a low cell potential of 1.49 V at 10 mA cm−2 for overall water splitting, which is even better than the noble metal based IrO 2 -Pt/C system. This contribution sheds light on boosting the catalytic activity of PBAs and metal-organic frameworks toward water splitting, sensors, and other energy-related applications. Image 1 • NiCo-PBA cubes built nanowalls are developed using Ni(OH) 2 nanosheets. • Showing excellent OER activity with 200 mV at 10 mA cm−2. • Ni atoms are active but Co atoms in [Co(CN) 6 ] are inactive during OER. • Demonstrating the impressive HER activity that is close to Pt/C. • Showing excellent bifunctionality for overall water splitting. [ABSTRACT FROM AUTHOR]

Abstract A novel biomaterial, polyglycerol grafted conducting polymer poly (3,4-ethylenedixythiophene) (PEDOT) was electrochemically synthesized. The PEDOT functionalized with hyperbranched polyglycerol (PEDOT-HPG) was simply prepared through the electrochemical polymerization of corresponding monomers, which was synthesized by grafting glycidol into (2,3-dihydrothieno[3,4-b][1,4]dioxin-2-yl)methanol (EDOT-MeOH). The antifouling properties of PEDOT-HPG surfaces were evaluated in terms of protein adsorption and the attachment of mammalian cells, including human cervical carcinoma cells (HeLa) and Michigan Cancer Foundation-7 (MCF-7). Through the conjugation of alpha-fetoprotein (AFP) antibodies to the PEDOT-HPG surfaces, sensitive immunosensors for AFP were fabricated, with the limit of detection at the level of 0.035 pg/mL. The prepared AFP biosensors exhibited excellent antifouling performance even in complex media and showed promising feasibility for the quantitative analysis of AFP in real samples. The PEDOT derivative with hyperbranched polyglycerol groups was effective to reduce biofouling and facile for surface functionalization. It is expected that this novel antifouling and conducting material may find broad applications in the development of electrochemical sensors and biosensors capable of assaying targets in complex biological media. Graphical abstract Sensitive and low-fouling electrochemical detection of alpha-fetoprotein was achieved based on antifouling and conducting PEDOT grafted with hyperbranched polyglycerol. Unlabelled Image Highlights • New polyglycerol grafted PEDOT derivative was electrochemically synthesized. • The PEDOT functionalized with hyperbranched polyglycerol showed excellent antifouling capability. • The AFP biosensor based on the PEDOT-HPG was capable of detecting target in human serum. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The design of combining photoanode with biocathode was proposed to develop a robust PEC immunosensor. • The TiO 2 -NTs/CIS(1:3)/CIS(1:40) photoanode has evident photocurrent response and good stability. • The PS@Ab 2 conjugates of the biocathode could significantly amplify the photocurrent signal. • The developed PEC immunosensor exhibited both of enhanced sensitivity and specificity. Abstract Highly sensitive and specific detection of biomarkers is of great importance for diagnosis and treatment of the related diseases or cancers. We herein developed a robust photoelectrochemical (PEC) immunosensor with enhanced sensitivity and specificity based on evident photocurrent output of the photoanode and significant signal amplification of the biocathode. Prostate specific antigen (PSA, Ag) was used as a target model to exhibit analytical performances of the designed PEC immunosensor. Two kinds of CuInS 2 quantum dots (CIS QDs) with different composition were modified on the TiO 2 nanotubes (TiO 2 -NTs) electrode to fabricate the photoanode. Due to the co-sensitization effect of the CIS QDs on TiO 2 -NTs, an evident photocurrent output was generated at the photoanode. For the biocathode, Au nanoparticles (AuNPs) and polydopamine (PDA) were modified in order on indium-tin oxide (ITO) electrode to immobilize capture PSA antibody (Ab 1). Carboxyl-modified polystyrene (PS) nanospheres were coated with secondary antibodies (Ab 2) to form PS@Ab 2 conjugates, which were used as signal amplifiers via the specific immunoreaction between Ag and Ab 2. Based on joint action of evident photocurrent output of the photoanode and significant signal amplification of the biocathode, the designed PEC immunosensor exhibited an ultralow detection limit of 3.4 fg/mL for target PSA detection. Meanwhile, it also showed an enhanced specificity owing to the separation of the photoanode and the biocathode. [ABSTRACT FROM AUTHOR]

A general, efficient strategy for a self-powered PEC immunoassay with an evident photocurrent response was proposed by separating the photoanode from recognition events. The immunoassay demonstrates the exciting features of both high sensitivity and anti-interference capabilities. [ABSTRACT FROM AUTHOR]

The double-network PVA-PPy hydrogels were prepared by the freeze-thawing and in-situ polymerization method. The PVA network and PPy network formed interpenetrating networks through hydrogen bonding and physical entanglement, which boosted the mechanical properties and ion diffusion characteristics. [Display omitted] The growing demands of flexible and wearable electronic devices boost the rapid development of flexible supercapacitors (FSCs). Conductive hydrogels are considered to be one type of promising electrode materials for FSCs due to their good processability and electrochemical properties. However, the poor mechanical properties of conductive hydrogels hinder their practical applications. Building robust cross-linked network structures is a feasible way to enhance their mechanical properties. Herein, the double-network polyvinyl alcohol (PVA)-polypyrrole (PPy) conductive hydrogels are synthesized by the freeze–thaw and in-situ polymerization method. The double-network structure not only enhances mechanical properties of the hydrogels, but also promotes their electrolyte ion transport. The maximum elongation at break of the optimized PVA-PPy hydrogels can reach 156.4%, and the specific capacitance is 1718.7 mF cm−2 at 0.5 mA cm−2. Furthermore, the energy densities of the symmetrical PVA-PPy FSCs are 46.7 and 13.3 μWh cm−2 at power densities of 200.0 and 2000.0 μW cm−2. Such excellent electrochemical performances and mechanical properties make the synthesized PVA-PPy hydrogels a promising candidate for FSCs. [ABSTRACT FROM AUTHOR]

Abstract: Novel porous spherical CuO xerogels constructed by crystalline nanorods (100–200nm in length and 20–40nm in diameter) are synthesized as anode materials in lithium-ion batteries. Aided with the soft-template of P123, the product possesses abundant mesopores centered at ~7.3nm and high surface area of 63.1m2 g−1. Benefiting from its structural features, including porous structure, one-dimensional structure, and oriented growth along (111) plane, the presented sample delivers high reversible capacity (646.7mAhg−1 at 0.2C after 150 cycles), excellent cyclic performance (88% capacity retention after 150 cycles), and superior rate capability (510mAhg−1 at 0.5C). [Copyright &y& Elsevier]

S-doped CoP nanoneedles assembled urchin-like structure on carbon cloth is prepared to demonstrate the boosting effects of nonmetal element doping and morphology controlling engineerings on OER performances for alkaline water splitting. [Display omitted] • S-doped CoP nanoneedles assembled urchin-like structure is grown on carbon cloth. • S doping brings more active sites and enhanced catalysis kinetics. • Nanoneedles assembled urchin-like structure benefit high surface area fast charge transfer. • Improved OER efficiency in alkaline media are obtained. The electrocatalysts with low-price and high-efficiency for oxygen evolution reaction (OER) are of significant importance for water splitting, which is believed as the promising technique for future sustainable energy system. Herein, sulfur is doped into carbon cloth supported CoP nanoneedles assembled urchin-like structure to acquire improved intrinsic catalysis efficiency, fast charge diffusion, and additional catalysis sites for enhanced OER performance. The specific urchin-like assembly structure is beneficial for highly exposed active sites and short charge transfer path for catalysis. Benefited from the advantages, the obtained sample exhibits advanced OER activity even better than RuO 2 in alkaline solution, achieving low overpotentials of 248 and 380 mV at current densities of 10 and 100 mA cm−2, respectively. This study may set a blueprint for exploring efficient transition metal pounds based catalyst for water splitting with nonmetal doping engineering. [ABSTRACT FROM AUTHOR]

• A smart cathodic aptasensor based on photoanode enhancement and nanocatalyst amplifier was proposed. • The co-sensitized structure of PEDOT/Bi 2 S 3 /ZnO photoanode achieved remarkable photocurrent response. • Pt nanocatalyst exhibited excellent catalytic ability for electron acceptor of oxygen reduction. • The elaborated cathodic aptasensor demonstrated excellent sensitivity, selectivity and anti-interference. Detection of targets in real samples with high sensitivity and accuracy is very important and a challenge for the application of developed biosensors. Herein, a novel and efficient cathodic aptasensor coupling photoelectrochemical (PEC) enhancement of photoanodes with signal amplification of nanocatalysts was elaborated. The model target of carcinoembryonic antigen (CEA) was employed to demonstrate the performance. A three-dimensional (3D) PEDOT/Bi 2 S 3 /ZnO photoanode was fabricated via successive modification of bismuth sulfide (Bi 2 S 3) nanosheets and a poly(3,4-ethylenedixythiophene) (PEDOT) layer on vertical zinc oxide (ZnO) nanorods. For the aptasensing cathode, after reduced graphene oxide (RGO) was deposited, the CEA aptamer was anchored on the cathodic substrate via the linking of chitosan. Part of the complementary DNA (cDNA) was labeled with Pt nanocatalyst to form the Pt-cDNA conjugate, which amplified the signal via DNA hybridization with the CEA aptamer. Target detection depended on a dramatic decrease in the current signal produced by both the escape of the signal amplifier and obvious steric hindrance of the captured CEA. Benefiting from the superior cosensitization structure of the photoanode and excellent catalytic ability for oxygen reduction of the labeled Pt nanocatalyst, the cathodic aptasensor demonstrated high sensitivity. Owing to the separation of the photoanode with biorecognition, the aptasensor also exhibited good selectivity in the biomatrix. This kind of cathodic aptasensor has offered an effective way to explore other high-performance biosensors for real applications. [ABSTRACT FROM AUTHOR]

Solidifying the soft lattice of all‐inorganic mixed‐halide perovskites is of great importance to restrain the notorious halide segregation under persistent light illumination. Herein, a multifunctional columnar macrocyclic molecule additive, namely cucurbituril into perovskite precursor to enhance the crystallization and reduce the defect density in the final perovskite film is introduced. Based on the theoretical calculation and simulation, the cucurbituril molecule with a strong double‐ended negatively‐charged cavity surrounded by terminated oxygen atoms not only coordinates with dangling Pb2+ ions to form host‐guest complexation but also induces an electric dipole field at perovskite grain boundary to effectively repel the iodide ion migration from the inside grain to the defective boundary, significantly suppressing the halide segregation and improving the device performance. As a result, the carbon‐based, all‐inorganic CsPbI2Br solar cell achieves an enhanced efficiency of 15.59% with great tolerance to environmental stresses. These findings provide new insights into the development of a novel passivation strategy with macrocyclic molecules for making high‐efficiency and stable perovskite solar cells. [ABSTRACT FROM AUTHOR]

Catalytic dehydrogenative coupling of thiols with amines to produce sulfenamides and disulfides is an important reaction in the industry. Classical synthesis of sulfenamides involves the reaction between amine nucleophiles and sulfonyl chlorides, which are not widely available, toxic and unstable, and the reaction requires a combination of oxidizing and chlorinating reagents. Here we decribe an environmentally benign protocol for the efficient electrochemical dehydrogenative coupling of thiols with amines or thiols to form compounds possessing S–N or S–S bonds. We used potassium iodide as electrocatalyst in methanol for a greener reaction. The reaction operates under ambient conditions in the absence of oxidants, acids/bases or toxic/explosive electrolytes. Results show that most produced sulfenamides and disulfides are generated in yields up to 99%. [ABSTRACT FROM AUTHOR]

An efficient signaling on–off mechanism was first proposed by integrating exciton–plasmon coupling and exciton energy transfer into cathodic PEC bioassays. This signaling on–off mechanism has endowed the cathodic PEC biosensor with powerful capability for ultrasensitive and specific detection of target DNA. [ABSTRACT FROM AUTHOR]

The present study reports an aqueous synthesis approach towards off-stoichiometric copper indium sulfide quantum dots with emissions in the near-infrared spectral range. The photoluminescence properties of the dots, and in particular the appearance of dual emission at high Cu deficiency, were studied with temperature-dependent steady-state and transient photoluminescence spectroscopy. [ABSTRACT FROM AUTHOR]

Wood derived carbon has been developed as promising host material for anchoring CoP@CoFe particles towards efficient OER application, which demonstrates widespread paradigm for constructing renewable and affordable hybrid materials for electrochemical energy storage and conversion. [Display omitted] • Natural wood derived carbon supported shell-core CoP@CoFe is designed for OER. • CoP@CoFe decorated on CW channels supplies large numbers of catalysis sites. • Integrating CoP@CoFe with CW supplies enhanced charge and mass flow. • Shell-core structure with interface effect improves intrinsic OER efficiency. • CoP@CoFe/CW exhibits overwhelming OER performance in alkaline media. Development of hybrid materials with specific architecture, interface, and multicomponent interactions demonstrates effective paradigm for pursuing high-performance energy conversion materials. Herein, using renewable and inexpensive wood-derived carbon as host, the shell-core CoP@CoFe particles are embedded on walls of carbonized wood channels (termed as CoP@CoFe/CW) to fabricate composite catalyst for electrocatalysis oxygen evolution reaction (OER). With benefits of the well distribution of CoP@CoFe particles, high conductivity of CW with channels, and good integration between them, highly exposed catalysis surface as well as rapid charge/mass transfer are achieved. The interface effect of shell-core hybrid activates the intrinsic OER efficiency of CoP@CoFe. Thus, the designed CoP@CoFe/CW yields excellent OER performance with ultralow overpotential of 120 mV (10 mA cm−2). This strategy of catalyst design based on eco-friendliness and renewable CW host may offer promising reference to explore composite materials with high conductivity and fast mass transfer for water electrolysis and other energy storage/conversion systems. [ABSTRACT FROM AUTHOR]

• Core-shell catalyst of graphene layer coated MoNi 4 -NiMoO 4 is developed. • High intrinsic activity and large ECSA are achieved. • Graphene layer accelerates charge transfer and benefits for durability. • Low overpotentials of 55 and 206 mV at 10 mA cm−2 for HER and OER. • High bifunctionality of 1.44 V at 10 mA cm−2 for overall water splitting. Developing active and cheap bifunctional electrocatalysts is crucial and challenging for overall water splitting. This work reports a core-shell structured catalyst supported on nickel foam, which is composed of hybrid MoNi 4 alloy and NiMoO 4 encapsulated in graphene shell layer. The core catalyst of MoNi 4 -NiMoO 4 supplies robust intrinsic activity and high conductivity. The graphene shell accelerates the charge transfer and provides additional protection for core catalyst. Hence, the present G@MoNi 4 -NiMoO 4 /NF exhibits excellent catalytic properties for alkali water splitting, with low overpotentials of 55 mV and 206 mV at 10 mA cm−2 for HER and OER, respectively. The efficient activity for overall water splitting is further demonstrated by a low cell voltage of 1.44 V at 10 mA cm−2 in the bifunctional G@MoNi 4 -NiMoO 4 /NF electrodes assembled electrolyzer, showing great promise for practical application. [ABSTRACT FROM AUTHOR]

Solid-state nanochannels have great potentials in the vibrant field of photoelectrochemical (PEC) bioanalysis. This work herein demonstrates the innovative use of DNA-decorated nanoporous anodic alumina (NAA) nanochannels for sensitive PEC bioanalysis of telomerase (TE) activity. Specifically, telomerase primer sequences (TS) were initially immobilized within the NAA nanochannels and then extended by TE in the presence of deoxyribonucleoside triphosphates (dNTPs). The as formed single-strand DNA was then directed to hybrid with many partially matched single-strand assisting DNA (aDNA), leading to the formation of multiple DNAzymes by the unmatched parts and the subsequent DNAzyme-stimulated biocatalytic precipitation (BCP) within the nanochannels. Because the inhibited signals of the photoelectrode could be correlated with TE-enabled TS extension, an innovative nanochannels PEC bioanalysis could be realized for probing TE activity. This work features the ingenious use of DNA-associated nanochannels for PEC bioanalysis of TE activity. Given the versatile functions of DNA molecules, the extension of this strategy easily allows for addressing numerous other targets of interest. Also, we envision this work could inspire more interest for the further development of nanochannels PEC bioanalysis. • An innovative PEC bioanalysis of telomerase activity was proposed based on solid-state nanochannels. • The AgIn 5 S 8 /TiO 2 /ITO photoelectrode exhibited evident photocurrent response and high stability. • Target-induced formation of multiple DNAzymes could evidently amplify the PEC detection signal. • This strategy could be extended easily for building nanochannels PEC bioanalysis toward other targets of interest. [ABSTRACT FROM AUTHOR]

This work reported an efficient one-pot hydrothermal method for adding promoter to nickel phyllosilicate. The nickel‑samarium bimetallic phyllosilicate (NiSm-Ps) was formed during the one-pot synthesis. The characterization results showed that the Sm species over the uncalcined NiSm-Ps catalyst existed in the form of Sm 2 Si 2 O 7 , and it was converted to be Sm 2 O 3 after calcination with high dispersion, and in the form of Sm 2 O x after reduction. On the contrary, for the post-impregnated Sm-doped nickel phyllosilicate catalyst (Ni-Ps/Sm-Im), the Sm species variation was from Sm 2 O 3 to Sm 2 O x , which was significantly different from that of NiSm-Ps. As a result, the NiSm-Ps catalyst showed a high Ni dispersion (13.9%), small particle size (4.0 nm) and large concentration of surface oxygen vacancies as well as strong H 2 and CO 2 activation properties. Consequently, the NiSm-Ps catalyst achieved a high CO 2 conversion of 80.1% at 400 °C and large TOF CO2 of 4.08 × 10−3 at 220 °C. Additionally, NiSm-Ps exhibited excellent long-term stability and anti-sintering property. In short, the formation of Sm 2 Si 2 O 7 was very crucial for the Ni-Sm/SiO 2 catalyst and could further improve the promotion effect of Sm species for CO 2 methanation. [Display omitted] • The Ni Sm bimetallic phyllosilicate catalyst was synthesized by a one-pot strategy. • Sm 2 Si 2 O 7 was the important intermediate product of the one-pot synthesized catalyst. • Sm 2 O 3 rather than Sm 2 Si 2 O 7 was observed on the post-impregnated catalyst. • The occurrence of Sm 2 Si 2 O 7 led to the more significant promotion effect for CO 2 methanation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Eco-friendly piperazine-based ionic liquids for extraction denitrogenation. • Clarification of denitrogenation mechanism by DFT and MD simulation. • [C 1 Pi][Lac] was completely renewable and reused for 4 times, still maintaining the great extraction denitrogenation performance. It is of great significance to develop sustainable denitrogenation technology due to the presence of nitrogen compounds in fuel oils which have serious impact on its quality. To avoid the problems of incomplete denitrogenation and harsh operating conditions associated with conventional hydrodenitrogenation (HDN) process. The extractive denitrogenation method was adopted with ionic liquids-based (ILs-based) materials as extractants in this work. Through an overall review comparison revealed that ILs-based extractants consisting of conventional imidazole-based cations and fluorine-containing anions were toxic and hazardous to the environment. Therefore, four eco-friendly piperazine-based ionic liquids (Pi-based ILs) were synthesized as denitrogenation extractants by one-step method. The performance of the synthesized IL extractants in removing pyrrole from oil was evaluated by removal efficiency (RE). The polarity of each molecule in the system and the interaction between ILs and pyrrole were also analyzed. The conformational relationship between the denitrogenation performance and the structure of the ILs was revealed. The results showed that eco-friendly 1-methyl-piperazine lactate ([C 1 Pi][Lac]) exhibited the highest RE among the four Pi-based ILs, with the RE of 95.90 % for pyrrole under the optimal denitrogenation conditions: m IL : m oil = 1, extraction temperature of 298.15 K, extraction time of 30 min, and standing time of 15 min. Then, the denitrogenation process was visual explored by the molecular dynamics (MD) simulation. In addition, [C 1 Pi][Lac] was regenerated and reused, which showed that the eco-friendly [C 1 Pi][Lac] could be completely regenerated and reused well. This study laid a solid foundation for the development of eco-friendly and sustainable denitrogenation process. [ABSTRACT FROM AUTHOR]

Highlights: [•] Mesoporous Co3O4 octahedra have been prepared with simple sol-gel method. [•] Porous structure buffers the volume change and shortens the diffusion path of Li+. [•] Anisotropy octahedral morphology guarantees structural stability. [•] It exhibits high capacity, superior capacity retention and excellent rate capability. [Copyright &y& Elsevier]

Developing novel catalysts with high efficiency and low cost for electrochemical hydrogen production is of great significance for sustainable energy applications. Herein, we present the exploratory research on nickel foam supported heterostructures of NiCo hydrogen carbonate (Ni 0.6 Co 0.4 (HCO 3) 2) with Pt nanoparticles on the surface for alkaline water hydrogen evolution reaction (HER). The heterogeneous engineering ensures effective synergism of moderate hydrogen adsorption energy, accelerated catalysis kinetics, improved active sites, and enhanced charge transfer, thus inducing excellent HER activity (56 mV at 10 mA cm−2 for geometric area and 15 mV at 10 mA cm−2 for electrochemical surface area) and stable durability. Notably, the mass activity of Pt in Pt–Ni 0.6 Co 0.4 (HCO 3) 2 is even higher than that of Pt/C. This study provides new insights into developing high-efficiency catalysts for hydrogen electrocatalysis, which also demonstrates that hydrogen carbonates are promising alternatives for electrochemical water splitting in addition to the widely focused transition metal hydroxides and oxides. • Ni 0.6 Co 0.4 (HCO 3) 2 is firstly hybridized with Pt for improved HER. • The electronic interaction moderates the hydrogen adsorption energy on Pt. • The intrinsic HER activity is activated. • Improved active sites density and enhanced charge transfer are acquired. • The mass activity of Pt in composite catalyst is higher than that of Pt/C. [ABSTRACT FROM AUTHOR]

• Heterostructure of Ru 2 P particles decorated Ni 2 P nanosheets is prepared. • Synergism induces accelerated kinetics and intrinsic activity. • Improved active sites density and enhanced charge transfer are obtained. • Showing robust activity and stability for HER in wide pH range. Lacking efficient and pH-universal catalysts is currently the main obstacle for the large-scale production of hydrogen through electrochemical water splitting. The hetero material of Ru 2 P nanoparticles and Ni 2 P nanosheets is constructed on carbon fiber cloth as pH-tolerant catalyst for hydrogen generation. The designed heterointerface provides synergism and structure advantages for improved intrinsic catalysis activity, more accessible active sites, and enhanced charge transfer for hydrogen evolution. The electrochemical measurements demonstrate the active hydrogen production properties, such as low overpotentials (46 mV, 47 mV, and 51 mV in 0.5 M H 2 SO 4 , 1 M KOH, and 1 M phosphate-buffered saline, respectively) at a current density of 10 mA cm−2, as well as rapid catalysis kinetics with small Tafel slopes and good stability. [ABSTRACT FROM AUTHOR]

• A one-pot colorimetric method based on the direct redox reaction of MnO 2 /glucose is proposed. • The MnO 2 nanomaterial is acted as not only an active nano-oxidizer but also an admirable color nano-indicator. • This system eliminates the addition of both the natural enzymes (GOx, peroxidase) and the color indicator. • This strategy may open a new avenue to build sensitive, low-cost and convenient method for the clinical applications. To establish more stable and lower cost colorimetric methods for the sensing of glucose, the artificial nanozymes were developed as the substitutes of natural enzymes (glucose oxidase, GOx; peroxidase). However, the common utilized nanozymes cannot show both the tandem enzymatic activities and the color indicating performance at the same time, which lead to the further addition of natural enzyme or color indicator. To overcome these problems, we fabricate a novel one-pot enzyme- and indicator-free method for the colorimetric sensing of blood glucose levels based on the direct redox reaction of MnO 2 /glucose. The MnO 2 nanomaterial is acted as an active nano-oxidizer, and a color nano-indicator for the sensing of blood glucose levels. In the presence of target glucose, the MnO 2 nano-oxidizers is reduced to Mn2+, leading to the dramatic decreasing absorbance and fading color of yellow MnO 2 solution. This nanosystem demonstrates wide liner range from 10 μM to 5 mM with low detectable limit of 10 μM. In addition, it shows favorable applicability for the glucose monitoring in human blood sample. Our proposed strategy takes advantage of the direct redox reaction of glucose and MnO 2 , which eliminates the use of natural enzymes (GOx, peroxidase) and the color indicator, and realized a sensitive, low-cost and convenient method for the colorimetric sensing of glucose. [ABSTRACT FROM AUTHOR]

An efficient but general strategy for antifouling photoelectrochemical cytosensor was proposed by introducing zwitterionic peptide. The cytosensor demonstrated the distinct merits of high sensitivity and low fouling in the biological media. • Zwitterionic peptide as antifouling material was first introduced in PEC biosensor. • The ITO/TiO 2 /ZnIn 2 S 4 electrode as PEC matrix had evident photocurrent response and good stability. • The PEC cytosensor exhibited high sensitivity and good antifouling capability in the biological media. • The application of antifouling biomaterials is a promising way to resist nonspecific adsorption or biofouling. Resulting from nonspecific adsorption or obvious biofouling, target detection in real biological media is a potential challenge for most of the biosensors. Herein, we first report an antifouling photoelectrochemical (PEC) cytosensor by using zwitterionic peptide. The typical cervical carcinoma Henrietta Lacks (HeLa) cell was chosen as a target model and the aptamer AS1411 was used as its recognition element. TiO 2 nanoparticles (NPs) and ZnIn 2 S 4 nanocrystals (NCs) were modified in order on a bare indium–tin oxide (ITO), forming ITO/TiO 2 /ZnIn 2 S 4 electrode as the PEC matrix to immobilize aptamer AS1411 and zwitterionic peptide. The fabricated PEC cytosensor exhibited a high sensitivity toward HeLa cell detection, with the detection limit of 34 cells/mL. Besides, owning to excellent antifouling property of the zwitterionic peptide, evidently reduced nonspecific adsorption of the cytosensor was realized in the biological media. [ABSTRACT FROM AUTHOR]

An electrochemical sensor for paracetamol is described that consists of a glassy carbon electrode (GCE) that was modified with the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with MnO2 nanoflowers. The hydrothermally synthesized MnO2 nanoflowers possess a large surface area and can be doped into PEDOT through electrochemical deposition to form a conducting polymer nanocomposite. The nanoflowers are shown to be uniformly distributed within the nanocomposite as revealed by elemental mapping analysis. The nanocomposite displays excellent catalytic activity toward the electrochemical oxidation of paracetamol. The modified GCE, best operated at a working potential of around 0.37 V (vs. SCE) has a linear response in 0.06 to 435 μM paracetamol concentration range and a very low limit of detection (31 nM at a signal-to-noise ratio of 3). The sensor exhibits excellent reproducibility and stability, and satisfying accuracy for paracetamol detection in pharmaceutical samples. [ABSTRACT FROM AUTHOR]

Molecular self-assembly has been regarded as a promising strategy for the construction of chiral sensing devices. Here, (1 R ,2 R)- N , N -didodecylcyclohexane-1,2-dicarboxamide (DDC) was synthesized and then self-assembled in alcohol, and a chiral helical structure could be formed owing to the intermolecular hydrogen bond and the polarity effect of solvent. The chirality of the resultant helical self-assembly was confirmed by circular dichroism (CD) spectra, and then the chiral helical self-assembly was used for electrochemical recognition of tryptophan (Trp) enantiomers. Due to the higher affinity of the self-assembly toward L-Trp than D-Trp, which was revealed by hydrophilicity evaluation, efficient recognition of the Trp enantiomers (I L-Trp / I D-Trp = 8.74) was achieved. Unlabelled Image • DDC is self-assembled in alcohol, and the self-assembly exhibits a helical structure. • Hydrogen bond and polarity effect of solvent contribute to the helical self-assembly. • Recognition of Trp enantiomers is achieved with the chiral helical self-assembly. • It opens up an avenue for the chiral analysis with artificial helical self-assembly. [ABSTRACT FROM AUTHOR]