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Photoelectrochemical biosensor for microRNA detection based on a MoS2/g-C3N4/black TiO2 heterojunction with Histostar@AuNPs for signal amplification
摘要： Herein, a novel photoelectrochemical (PEC) biosensor was developed for the ultrasensitive detection of microRNA-396a based on a MoS2/g-C3N4/black TiO2 heterojunction as the photoactive material and gold nanoparticles carrying Histostar antibodies (Histostar@AuNPs) for signal amplification. Briefly, MoS2/g-C3N4/black TiO2 was deposited on an indium tin oxide (ITO) electrode surface, after which gold nanoparticles (AuNPs) and probe DNA were assembled on the modified electrode. Hybridization with miRNA-396a resulted in a rigid DNA:RNA hybrid being formed, which was recognized by the S9.6 antibody. The captured antibody can further conjugate with the secondary IgG antibodies of Histostar@AuNPs, thereby leading to the immobilization of horse radish peroxidase (HRP). In the presence of HRP, the oxidation of 4-chloro-1-naphthol (4-CN) by H2O2 was accelerated, producing the insoluble product benzo-4-chlorohexadienone on the electrode surface and causing a significant decrease in the photocurrent. The developed biosensor could detect miRNA-396a at concentrations from 0.5 fM to 5000 fM, with a detection limit of 0.13 fM. Further, the proposed method can also be used to investigate the effect of heavy metal ions on the expression level of miRNAs. Results suggest that the biosensor developed herein offers a promising platform for the ultrasensitive detection of miRNA.
关键词： S9.6 antibody,Histostar@AuNPs,MicroRNA detection,MoS2/g-C3N4/black TiO2 heterojunction,Photoelectrochemical biosensor
更新于2025-11-14 17:04:02
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A microfluidic all-vanadium photoelectrochemical cell with the N-doped TiO2 photoanode for enhancing the solar energy storage
摘要： In this work, the nitrogen-doped TiO2 photocatalyst is synthesized and applied in a microfluidic all-vanadium photoelectrochemical cell for enhancing the solar energy storage. The use of the nitrogen-doped TiO2 photoanode and the minimization design can ensure the visible-light response, increased specific surface area, vigorous pore structure and enhanced photon and mass transport as well as more uniform light distribution. Various characterizations are performed to evaluate the developed photocatalyst and microfluidic all-vanadium photoelectrochemical cell. The results confirm that the developed nitrogen-doped TiO2 photoanode can provide both the extended absorption spectrum and the small anatase crystal size as well as the obviously enlarged specific surface area with plentiful pore structure. Because of these merits, the microfluidic all-vanadium photoelectrochemical cell with the nitrogen-doped TiO2 photoanode yield the average photocurrent density of 0.103 mA/cm2 during the long-term operation, which is much higher than those with the un-doped TiO2 photoanode (0.086 mA/cm2) and commercial P25 TiO2 photoanode (0.073 mA/cm2), presenting 19.8% and 41% improvements, respectively. The results demonstrate not only the promotion of the vanadium reversible redox pairs conversion but also the inherently excellent stability by the nitrogen-doped TiO2 photoanode.
关键词： Photoanode,N-doped TiO2 photocatalyst,Conversion rate,Microfluidic all-vanadium photoelectrochemical cell,Solar energy storage
更新于2025-11-14 17:03:37
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Near-infrared-light-triggered photoelectrochemical biosensor for detection of alpha-fetoprotein based on upconversion nanophosphors
摘要： A novel photoelectrochemical (PEC) biosensor based on hybrids of NaYF4:Yb, Tm， zinc oxide (ZnO) and cadmium sulfide (CdS) was constructed to detect alpha-fetoprotein (AFP), which possesses the advantages of low background noise and non-damage to the biological substance. Herein, we prepared NaYF4:Yb,Tm/ZnO/CdS composite film electrode by pulsed laser deposition. The selected materials of ZnO and CdS can make full use of the upconversion luminescence (~360nm, ~480nm) of NaYF4:Yb,Tm nanophosphors under 980nm laser excitation. Meanwhile, an effective matching of energy levels between the conduction bands of CdS and ZnO can prompt photoelectrochemical performance of the electrode. The biosensor shows ultrasensitive detection of AFP with a wide linear range from 0.01 ng mL-1 to 200 ng mL-1 and a low detection limit of 5 pg mL-1. Therefore, the proposed PEC biosensor based on upconversion nanophosphors is potentially attractive for achieving excellent photoelectrochemical biosensor for detection of other cancer markers in clinical analysis.
关键词： photoelectrochemical,pulsed laser deposition,upconversion luminescence,near-infrared light-triggered biosensor
更新于2025-11-14 15:27:09
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Photoelectrochemical enhancement from deposition of BiVO4 photosensitizer on different thickness layer TiO2 photoanode for water splitting application
摘要： TiO2 is a prominent photocatalyst and has been pioneering the research in water splitting for hydrogen cell production. However, TiO2 has low visible region absorption which limit its functionality as a photoabsorber and requires addition of other high absorptive material such as BiVO4. Fabrication of TiO2 photoanode on FTO substrate and deposition of BiVO4 on TiO2 were done using simple spin coating procedure. TiO2/BiVO4 photoelectrode were first tested for its photo absorption, photocurrent generation and electrical impedance to obtain the optimized sample. Optimized sample then further tested for its photocurrent generation stability using linear sweep voltammetry and time dependent photocurrent test. Photo absorption enhancement from TiO2/BiVO4 of almost 10 folds achieved along the visible region comparing to pure TiO2. Photogenerated charge produced from TiO2/BiVO4 is also 3 folds higher compared to pure TiO2at water oxidation threshold potential at 1.23 V vs. RHE. From photocurrent generation analysis, heterostructure of TiO2/BiVO4 proven to produce more than 3 folds higher photocurrent comparing to both pure TiO2 and BiVO4.
关键词： Z-scheme,Bismuth vanadate,Thin-film,Titanium dioxide,Photoelectrochemical water splitting
更新于2025-11-14 15:19:41
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Quenched Sandwich-type Photoelectrochemical Aptasensor forProtein Detection based on Exciton Energy Transfer
摘要： This work proposes a quenched photoelectrochemical sensing method for highly selective and sensitive detection of protein via Energy Transfer (ET) effect between the AuNPs and CdS:Mn quantum dots. This detection was performed on a sandwich-type aptamer sensing interface. Chitosan modified CdS:Mn/TiO2/ITO electrode was used to immobilize capture DNA (S1) via -CONH- bond. In the presence of target protein, AuNPs labeled DNA (AuNPs-S2) was further bonded to the protein to fabricate sandwich sensing platform, which forced the AuNPs away from the electrode surface. In this state, the photocurrent was greatly depressed, mainly due to two factors: (a) the ET effect produced by interparticle distance between CdS:Mn and AuNPs; (b) the steric hindrance of AuNPs-S2 partly obstructs the diffusion of the electron donor. The photocurrent decreased with the increasing concentration of the target protein. Using thrombin as a target, this sensitized method showed a detectable range of 0.1 pM to 8 nM and a detection limit of 30 fM. It possessed high selectivity and good stability for detection of thrombin. This method is extremely flexible and can be extended to varieties of protein targets.
关键词： CdS:Mn,Photoelectrochemical aptasensor,Thrombin,Energy transfer,AuNPs
更新于2025-11-14 15:15:56
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High Temperature One-Step Synthesis of Efficient Nanostructured BiVO4 Photoanodes for Water Oxidation
摘要： Bismuth vanadate (BiVO4) is a promising photoanode material for photoelectrochemical water splitting due to its well-suited valence band edge and comparatively narrow band gap. Herein, we provide first insights on the high temperature rapid and scalable synthesis of efficient nanostructured BiVO4 photoanodes for water oxidation. Nanostructured BiVO4 films with tunable optical density and porosity from 12 to 80% have been synthesized in few seconds by direct deposition of flame-made BiVO4 nanoparticle aerosols. The impact of BiVO4 film structural properties on the photooxidation performance has been systematically investigated by a set of electrochemical and physical characterizations indicating key directions for its morphological optimization. It was found that the BiVO4 water oxidization performance is mainly determined by two competitive factors, viz. accessible surface area and carrier conductivity through the grain boundaries. Optimization of these two factors increased the photocurrent densities by more than 3 times resulting in ca 1.5 mA cm-2 for sulphite oxidation and ca 1 mA cm-2 for water oxidation with a FeOOH\NiOOH co-catalyst at 1.0 V vs. the reversible hydrogen electrode (VRHE) under simulated one sun illumination. These findings provide novel insights into the structure-activity relationships of high temperature synthesized BiVO4 photoanodes for solar-powered water splitting, and introduce a scalable and low-cost approach for their rapid nanofabrication.
关键词： Flame Synthesis,Bismuth Vanadate,Scalable,One-Step,Photoelectrochemical Water Splitting
更新于2025-10-22 19:40:53
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Plasmonic nickel nanoparticles decorated on to LaFeO3 photocathode for enhanced solar hydrogen generation
摘要： Plasmonic Ni nanoparticles were incorporated into LaFeO3 photocathode (LFO-Ni) to excite the surface plasmon resonances (SPR) for enhanced light harvesting for enhancing the photoelectrochemical (PEC) hydrogen evolution reaction. The nanostructured LFO photocathode was prepared by spray pyrolysis method and Ni nanoparticles were incorporated on to the photocathode by spin coating technique. The LFO-Ni photocathode demonstrated strong optical absorption and higher current density where the untreated LFO film exhibited a maximum photocurrent of 0.036 mA/cm2 at 0.6 V vs RHE, and when incorporating 2.84 mmol Ni nanoparticles the photocurrent density reached a maximum of 0.066 mA/cm2 at 0.6 V vs RHE due to the SPR effect. This subsequently led to enhanced hydrogen production, where more than double (2.64 times) the amount of hydrogen was generated compared to the untreated LFO photocathode. Ni nanoparticles were modelled using Finite Difference Time Domain (FDTD) analysis and the results showed optimal particle size in the range of 70e100 nm for Surface Plasmon Resonance (SPR) enhancement.
关键词： LaFeO3,Finite difference time domain,Surface plasmon resonance,Ni nanoparticle,Photocathode,Photoelectrochemical water splitting
更新于2025-10-22 19:40:53
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Influence of thermal oxidation temperature on the microstructure and photoelectrochemical properties of ZnO nanostructures fabricated on the zinc scraps
摘要： In this paper, zinc oxide (ZnO) nanowires were synthesized by thermal oxidation method of zinc scrap at various temperatures ranging between 400 °C and 900 °C under air atmosphere. The influence of different temperature on the phase structures, surface morphologies and photoelectrochemical (PEC) properties of ZnO nanowires were investigated. The characterizations were carried out via X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX). The results showed that annealing temperature played a significant role on surface morphology and phase structure. The band gap energy of the ZnO nanowires changed between 3.12 and 3.194 eV. The photoelectrochemical (PEC) study of the ZnO nanowires was investigated in 0.1 M Na2SO4 aqueous solution. The PEC findings represented that the ZnO nanowire annealed at 600 °C had 252.2 mA/cm2 net photocurrent density which was the best efficiency and at least 10 times higher than that of the lowest one at 1.25 V (vs. VRHE). Mott-Schottky analysis showed that the ZnO nanowires behaved as n-type semiconductor. ZnO nanowire annealed at 600 °C had the highest carrier density value (Nd = 9.03 × 10^23). Moreover, the charge transfer behavior of the ZnO nanowires was determined by means of electrochemical impedance spectroscopy (EIS) measurements. As a result, this work recommends that the ZnO nanowires could be good candidate on PEC applications. Also, thermal oxidation method is an efficient method for fabrication of ZnO nanowires.
关键词： Thermal oxidation,Zn scrap,Electrochemical impedance spectroscopy (EIS),ZnO nanowires,Photoelectrochemical (PEC)
更新于2025-09-23 15:23:52
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A high-performance photoelectrochemical water oxidation system with phosphorus doping g-C3N4 and simultaneous metal phosphide cocatalyst formation via a gas treatment
摘要： Graphitic carbon nitride (g-C3N4) has been widely explored as photocatalyst for water splitting. The anodic water oxidation reaction (WOR) remains the major obstacle for such process, with particular issues on low surface area of g-C3N4, poor light absorption as well as low charge transfer efficiency. In this work, such longtime concerned issues have been partially addressed with band gap and surface engineering of nanostructured graphitic C3N4. Specifically, surface area and charge transfer efficiency are significantly enhanced via architecturing g-C3N4 on nanorod TiO2 to avoid the aggregation of layered g-C3N4. Moreover, a simple phosphide gas treatment of TiO2/g-C3N4 configuration not only narrows the band gap of g-C3N4 by 0.57 eV into visible range, but also in-situ generates a metal phosphide (M=Fe, Cu) water oxidation cocatalyst. This TiO2/g-C3N4/FeP configuration significantly improves charge separation and transfer capability. As a result, our photoelectrochemical system yields outstanding visible light (> 420 nm) photocurrent: ca. 0.3 mA·cm-2 at 1.23 V and 1.1 mA·cm-2 at 2.0 V vs RHE, the highest using g-C3N4 as photoanode. We expect that our TiO2/g-C3N4/FeP configuration generating via simple phosphide gas treatment will bring in new insight for robust g-C3N4 for water oxidation.
关键词： doping,photoelectrochemical,cocatalyst,g-C3N4,high performance
更新于2025-09-23 15:23:52
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Facet effect on the photoelectrochemical performance of a WO3/BiVO4 heterojunction photoanode
摘要： Different WO3 facets have different surface energies and electronic structures, and exhibit different water oxidation abilities and photocatalytic performance as a result. Because of the material’s limited photoresponse region, loading a narrow bandgap material on WO3 is a generally known method for improving photo-harvesting. In this paper, we have synthesized WO3 films with different crystal facet ratios. After loading BiVO4 on these WO3 films, we measured the photoelectrochemical (PEC) performance to investigate the effects of WO3 facet choice on the heterojunction film electrode’s performance. We found that a high-intensity ratio of the (002) WO3 facet in X-ray diffraction (XRD) leads to a more negative onset potential and higher photocurrents in a lower potential region. The ultraviolet photoelectron spectra show a lower work function for the 002-dominant WO3 film compared to other WO3 films, which may result in a higher quasi-fermi level for the heterojunction electrode. Based on the XRD results, the high-intensity ratio of the (002) WO3 facet preferentially exposes the (020) BiVO4 facet, which may be a reason for the better charge extraction observed at low applied potential and high faradic efficiency on PEC water splitting. Together, this results in a high hole injection efficiency for 002-dominant WO3/BiVO4 films compared with WO3/BiVO4 films favoring other WO3 facet ratios.
关键词： BiVO4,WO3,Photoelectrochemical performance,Facet effect,Heterojunction
更新于2025-09-23 15:23:52