Search

Accurate measurement of cancer markers in urine is a convenient method for tumor monitoring. However, the concentration of cancer markers in urine is so low that it is difficult to achieve their measurement. Photoelectrochemical (PEC) sensors are a promising technology to realize the detection of trace cancer markers due to their high sensitivity. Currently, the interference of nonspecific biomolecules in urine is the main reason affecting the high sensitivity and selectivity of PEC sensors in detecting cancer markers. In this work, a strategy of oxygen vacancy (OV) modulation is proposed to construct a fouling-resistant PEC aptamer sensing platform for the detection of α-fetoprotein (AFP), a liver cancer marker. The introduction of OVs induces the formation of intermediate localized states in the photoelectric material, which not only facilitates the separation of photogenerated carriers but also leads to the redshift of the light absorption edge. More importantly, OVs with positive electrical properties can be employed to modify the antifouling layer (C-PEG) with negatively charged groups through an electrostatic interaction. The synergistic effect of OVs, antifouling layer, and aptamer resulted in a TiO2/OVs/C-PEG-based PEC sensor achieves a wide linear range from 1 pg/mL to 100 ng/mL and a low detection limit of 0.3 pg/mL for AFP. In addition, the sensor successfully realized the determination of AFP in urine samples and accurately differentiated between normal people and liver cancer patients in the early and advanced stages. This project is of great significance in advancing the application of photoelectrochemical bioanalytical technology to achieve the detection of cancer markers in urine by investigating the construction of an OVs-regulated fouling-resistant sensing interface.

Thermal quenching performance is a huge challenge in the application of phosphor materials. In this paper, the relationship between the energy gap of luminescent ions and the thermal quenching activation energy (ΔE) is discussed from the angle of energy-level splitting for the first time. When the proportion of coordination cations (Nb–Ta) in the matrix is adjusted, the dissimilarity in bond lengths and bond angles of the two crystal configurations (NbO6/TaO6) makes the crystal electron cloud expand, the decrease in atomic orbital overlap reduces the covalency, and the nephelauxetic effect enlarges the bond length between the dopant and the ligand, thus decreasing the crystal field splitting energy of trivalent bismuth ions, which weakens the splitting degree of the P energy level, leading to an increase in the energy gap from 3.854 to 4.101 eV. Interestingly, the thermal quenching performance of YNb1–xTaxO4:Bi3+(YNTO:Bi3+) also changes with the Nb–Ta ratio, and the thermal quenching activation energy is positively correlated with the energy-gap value. Guided by the density functional theory calculations on the ligand structure, we establish the functional relationship between the energy-gap value and ΔE; the tuning of the thermal quenching activation energy of the Bi-doped phosphors from 0.473 to 0.543 eV is realized by controlling the ratio of Nb5+/Ta5+. The Bi3+–Eu3+double-doped white-light-emitting phosphors prepared according to this mechanism can still emit warm white light at 463 K. The topological chemical design of the ligand configuration realizes the modulation of the thermal quenching activation energy, and this method can be used as a model to design various novel ΔE-adjustable fluorescent powder materials.

Solar-driven overall water splitting is highly desirable for hydrogen generation with sustainable energy sources, which need efficient, earth-abundant, robust, and bifunctional electrocatalysts for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, we propose a heterogeneous bimetallic phosphide/sulfide nanocomposite electrocatalyst of NiFeSP on nickel foam (NiFeSP/NF), which shows superior electrocatalytic activity of low overpotentials of 91 mV at −10 mA cm–2for HER and of 240 mV at 50 mA cm–2for OER in 1 M KOH solution. In addition, the NiFeSP/NF presents excellent overall water splitting performance with a cell voltage as low as 1.58 V at a current density of 10 mA cm–2. Combining with a photovoltaic device of a Si solar cell or integrating into photoelectrochemical (PEC) systems, the bifunctional NiFeSP/NF electrocatalyst implements unassisted solar-driven water splitting with a solar-to-hydrogen conversion efficiency of ∼9.2% and significantly enhanced PEC performance, respectively.

Photoelectrochemical (PEC) water splitting is a promising technique for sustainable hydrogen generation. However, PEC performance on current semiconductors needs further improvement. Herein, a phosphorus cation doping strategy is proposed to fundamentally boost PEC performance on TiO2nanotube photonic crystal (TiO2NTPC) photoelectrodes in both the visible-light region and full solar-light illumination. The self-supported P-TiO2NTPC photoelectrodes are fabricated by a facile two-step electrochemical anodization method and subsequent phosphidation treatment. The Ti4+is partially replaced by P cations (P5+) from the crystal lattice, which narrows the band gap of TiO2and induces charge imbalance by the formation of Ti–O–P bonds. We believe the combination of unique photonic nanostructures of TiO2NTPCs and P cation doping strategy will open up a new opportunity for enhancing PEC performance of TiO2-based photoelectrodes.

Red-emitting phosphor is the main component material of white light-emitting diodes (WLEDs), enhancing its thermostability is a key challenge to improve the lighting quality. In this work, a strategy of constructing multi-level electron traps to compensate for fluorescence thermal quenching is proposed, and the Eu3+-doped phosphor host was modified by polycrystalline crystals. Owing to the asymmetry of coordination cation configuration in the host, atomic dislocations occur in the local spatial region resulting in an increase in cationic disorder, thus forming multi-level electron traps. The multi-level electron traps release electrons at different temperatures to compensate for the thermal quenching of Eu3+luminescence, which results in a reciprocating change in the Eu3+PL intensity. At 523 K, the relative emission intensity of Eu3+dominant peak reaches 0.75 (λex = 394 nm peak:610–619 nm), and the maximum relative emission intensity reaches 0.99 (λex = 465 nm peak:700–714 nm), which indicates that the phosphor has excellent thermostability. These results manifest that the multi-level electron traps formed by modifying the activator host with polycrystalline crystals can greatly improve the thermostability of phosphors, which provides a new route for preparing phosphors with excellent thermostability.