Organic photodetectors (OPDs) are emerging as promising candidates for flexible and low-cost sensing applications, but their performance is often limited by trap-induced dark current and unstable interfacial energetics. Here, we systematically studied the defect evolution of classical ZnO electron transport layers and revealed a "resting effect". Direct and indirect evidence proved that Long-term air aging or strong light activation can effectively mitigate oxygen-vacancy-related shallow trap states and narrow the interfacial energetic disorder. This reduction in energetic disorder is beneficial to charge extraction in the corresponding devices. Furthermore, PDINN interfacial modifier was introduced to passivate residual defects and form a favorable dipole to optimize energy-level alignment. The resulting OPDs deliver a high peak specific detectivity (∼8.30 × 1013 Jones) with suppressed dark current density, microsecond-scale response, and stable operation, and the performance-improvement trends remain consistent across several representative non-fullerene active layers beyond BTP-series derivatives (including IDIC, ITIC-4Cl, and PC61BM). Integrated into a wearable self-powered platform, the optimized devices enable high-fidelity pulse acquisition with a signal-to-noise ratio above 25 dB. Coupled with a residual-attention neural network (OPDPulseNet), the system accurately classifies motion-induced pulse patterns with an accuracy of 97.14%. Overall, we connect ZnO defect-state regulation and PDINN interfacial tuning to traps, noise spectra, and noise-limited detectivity, and further demonstrate the benefits for high-SNR wearable pulse sensing.

The quantitative determination of cholesterol in foods, drugs, and biological fluids holds significant importance due to its potential health risks. Herein, a self-powered photoelectrochemical (PEC) sensor was developed for cholesterol detection. The photoelectrochemical system was constructed by modifying fluorine-doped tin oxide (FTO) electrodes with ZnO/C (serving as the photoanode) and iron-modified CuBi2O4 (denoted as CBFO, functioning as the photocathode) through a controlled deposition process. To enhance detection selectivity, molecularly imprinted polymers (MIPs) were electrodeposited on the photocathode surface. The optimized sensor exhibited a linear detection range of 1-1000 nmol L-1 and a detection limit of 0.26 nmol L-1 (S/N = 3). Practical application of the sensor for cholesterol detection in milk samples demonstrated satisfactory recovery rates (98.6 %-107 %) with relative standard deviations (RSD) ranging from 2.38 % to 4.25 %. These results underscore the potential of this self-powered PEC sensor as a robust platform for rapid and accurate cholesterol determination in food products, pharmaceuticals, and environmental samples.

Tactile perception, dominated by human skin, plays an important role in human-nature interaction, especially when visual perception is limited. The key to mimicking skin tactile perception is to address skin-like properties of materials and integration of biomimetic tactile functions. To be competent in bionic skin, composite silk fibroin (SF) films possessing high tensile properties (159.71 %) and hydrogels with elasticity (54.42 %) were prepared through a mesoscopic reconstruction strategy of SF materials, using fish scale gelatin molecules as mesoscopic templates to regulate the nucleation and crystallization kinetics of SF molecules. In addition, inspired by the mechanoreceptors, a bimodal protein bionic skin (BPBS) was prepared by horizontally integrating a single-electrode triboelectric sensor and a capacitive sensing array, which can work in sliding and pressing modes to mimic the sliding touch and pressing touch of the finger, respectively. The system achieves a 99 % Braille recognition accuracy in sliding mode through a deep learning algorithm, and Bluetooth technology enables real-time wireless Braille recognition in pressing mode, synergistically enhancing the robustness and practicality of BPBS. This research provides novel insights into enhancing human touch perception, human-computer interaction, and the advancement of intelligent prosthetics, marking a significant stride in the development of bionic skins with multimodal sensing capabilities.

The charge dissipation effect induced by the surrounding water not only severely reduces the output of the triboelectric nanogenerators (TENGs), but also impacts their stability and durability, significantly limiting their application. Therefore, developing humidity-resistant triboelectric nanogenerators (HRTENGs) is an urgent issue to improve the environmental adaptability of TENGs. Herein, a novel HRTENG was designed with amino-oxidized sodium alginate (OSAN) that achieves enhanced electrical output properties from 15% RH to 85% RH, accompanying excellent reversible property and outstanding water resistance ability. The enhancing dielectric property by introducing of aldehyde groups direct improves the output of the TENG, and the hydrophilicity improvement by modified with the amino side chains induces the formation of bound water, resulting in charge dissipation effect weakening and contact charging strengthening, further increasing the output of the HRTENG. At 50% RH, the electrical output of the HRTENG fabricated with OSAN3G0.5 is nine times compared to the TENG made with SAG0.5. The HRTENGs were used to monitor motion and respiratory status and could also clearly identify sleep issues for patients suffering from obstructive sleep apnea-hypopnea syndrome. The HRTENG we constructed provides a reference for future wearable self-powered devices for motion management, respiratory monitoring, disease diagnosis, and rehabilitation treatment.

Highly fluorescent carbon nanodots (CNDs) have broad application prospects in optoelectronics, energy, biological imaging, and other fields because of their good solubility in water, adjustable photoluminescence (PL), low toxicity, good biocompatibility, and stable chemical properties. In this paper, polyethyleneimine@CNDs (PEI@CNDs) with unique excitation- and concentration-dependent PL properties were synthesized by a one-pot hydrothermal approach. The morphology, structure, surface chemistry, photophysical properties, and stability of the PEI@CNDs were well probed. The PEI@CNDs solution at low concentration displayed blue PL with a quantum yield of 50.6%. As the concentrations of the PEI@CNDs increase, the PL colors changed from blue, cyan, and green, to greenish-yellow. At low concentration, the excitation-independent and excitation-dependent PL property is mainly caused by carbon core and surface state emission. However, at higher concentration, the quenched blue emission and enhanced green emission were found. This is mainly attributed to the aggregate-related inner filter effect, electron transfer, and surface states. Mixing 10.0 mg/mL of PEI@CNDs with polyvinyl alcohol can be used to construct composite films, which were combined with the blue light-emitting diode to construct white light-emitting diodes with white and warm white emissions.

CuS nanoparticles (CuS NPs) have excellent photo thermal conversion effects due to their strong and wide-band light absorption. The composite of CuS NPs may enhance the light absorption and photoheating effect, and their broad applications have appealed to wide interests. In this paper, ethylene imine polymer (PEI)-linked graphene quantum dots (PEI_GQDs) were easily obtained by an ultrasonic-assisted hydrothermal approach, and CuS nanoshells (NSs) were prepared with Cu2O NSs as a template. The composite of CuS@PEI_GQDs NSs was easily obtained by self assembly due to the electrostatic attraction between PEI_GQDs and CuS NSs. The morphology, structure, surface chemistry, and optical absorption of the prepared nanomaterials were characterized by multi microscopic techniques. The results of high-resolution transmission electron microscope (HRTEM), X-ray diffractometer (XRD), Fourier transform infrared (FTIR), X-ray photoelectronic spectroscopy (XPS), and energy-dispersive spectrum (EDS) show that the PEI_GQDs were successfully linked on the surfaces of the CuS NSs; the FTIR analysis reveals that there is an interaction between CuS NSs and PEI_GQDs by chelation between Cu2+ and -NH2 in PEI_GQDs. The pore size distribution indicated that both the CuS NSs and CuS@PEI_GQDs NSs contained mesopores in the wall shells. The CuS@PEI_GQDs NSs displayed enhanced absorption within 190-500 and 630-1100 nm compared to the CuS NSs. The photoheating effects of CuS@PEI_GQDs NSs and CuS NSs were investigated under 808 nm laser and sunlight irradiation, and CuS@PEI_GQDs NSs presented a better photoheating effect and photothermal stability than CuS NSs. Our results provide a facile approach to fabricate other GQD-coated nanomaterials. The excellent photoheating effects of CuS@ PEI_GQDs NSs are promising in photothermal conversion.

In this work, a molecularly imprinted polymer (MIP)-based photoelectrochemical (PEC) sensor for the detection of ciprofloxacin (CIP) was constructed. Carbon-modified ZnO (ZnO/C) nanocomposite with adjustable zinc content was prepared by a carbonaceous method, facilitating visible light absorption and electron transition. The structure, morphology, and surface chemistry of ZnO/C were well characterized. The MIP membrane was formed by electropolymerizing, with ZnO/C nanocomposite, o-phenylenediamine (C6H4(NH3)2,o-PD), and CIP as highly efficient photoactive materials, functional monomer, and template, respectively. The PEC properties of different photoactive electrodes were measured and analyzed. The MIP-based PEC sensor showed excellent sensitivity and selectivity towards CIP, displaying a broad linear range from 0.01 nM to 1000 nM, a low detection limit of 8.41 pM, and satisfied recovery rates within 96.8%103.2%. The sensor exhibited reliable reproducibility and stability, with a relative standard deviation (RSD) of 2.48% for the CIP in milk. The constructed MIP-based PEC sensor not only provides a powerful and reliable route for the detection of CIP, but also can be extended to detect other antibiotics in food and natural environment.

The negative effects of environmental estrogens on wildlife and human beings are gaining increasing attention. Research on the highly sensitive detection method for Vitellogenin (Vtg), one of the biomarkers of environmental estrogens (EEs), is expected to detect weak estrogens in complex environments. This study aimed to develop a label-free immunosensor with high specificity and sensitivity for testing Vtg. Carbon quantum dots (CQDs) with high fluorescence and excellent stability were synthesized, and antilipovitellin monoclonal antibody (Anti-Lv-mAb) was prepared. Based on the fluorescence resonance energy transfer (FRET) between CQDs-conjugated Anti-Lv-mAb and reduced graphene oxide (RGO), an ultrasensitive fluorescent “ON-OFF” label-free immunosensor for detection of Vtg of marine medaka was established. By modification of RGO with poly dimethyl diallyl ammonium chloride (PDDA), the Zeta potential of RGO was changed and the FRET efficiency was improved. The immunosensor displayed a wide linear response to Vtg of marine medaka from 0.1 to 3000 ng/mL, a low limit of detection (LOD) of 0.04 ng/mL, and excellent sensitivity (28,833.63 CPS/(ng/mL)), selectivity, and reproducibility. The results demonstrated that the fluorescent “ON-OFF” immunosensor is an easy-to-use, relatively fast, ultrasensitive, and accurate detection method for weak estrogenic activity.

Background: It is meaningful to use semiconductor nanomaterials for degradation of organic compounds under irradiation of solar light. Introduction: Nano Cu2O is suitable for visible-light photocatalysis for the narrow band gap (~2.17 eV). However, few focus on the morphology changes of Cu2O in the process of photocatalysis. Methods: By two-step addition of reducer, porous Cu2O nanoshells (NSs) with almost 100% hollow structure were synthesized, characterized and used to photocatalyze MO in neutral solution at 30 C in air. Results: Cu2O NSs have high adsorption and good photocatalysis rates for MO. After photocatalysis, some new results were observed. Most chemical bonds of MO were broken, but part of sulfur containing group of MO left on the NSs. The morphology of Cu2O NSs was changed and lots of nanodebris was produced. Further experimental results showed some nanodebris was also observed after adsorption-desorption equilibrium (ADE). Without MO and only light irradiation of Cu2O suspension, little nanodebris appeared. The results of X-ray diffraction (XRD), scanning transmittance electron microscope (STEM) and high-resolution transmittance electron microscope (HRTEM) proved the composite of the nanodebris is Cu2O. The nanodebris are the nanosheets dropped off from the Cu2O NSs. Conclusion: For the porous Cu2O NSs are composed of Cu2O nanosheets with exposed 111 facets, which have strongest adsorption ability for MO and strongest catalysis performance. Light irradiation sped up this interaction and led to the Cu2O nanosheets dropping off from the Cu2O NSs. For the strong interaction between Cu+ and S, part of sulfur containing group of MO left on the NSs after photocatalysis.

The increasing levels of environmental estrogens are causing negative effects on water, soil, wildlife, and human beings; label-free immunosensors with high specificities and sensitivities are being developed to test estrogeneous chemicals in complex environmental conditions. For the first time, highly fluorescent graphene quantum dots (GQDs) were prepared using a visible-Fenton catalysis reaction with graphene oxide (GO) as a precursor. Different microscopy and spectroscopy techniques were employed to characterize the physical and chemical properties of the GQDs. Based on the fluorescence resonance energy transfer (FRET) between amino-functionalized GQDs conjugated with anti-lipovitellin monoclonal antibodies (Anti-Lv-mAb) and reduced graphene oxide (rGO), an ultrasensitive fluorescent “ON-OFF” label-free immunosensor for the detection of lipovitellin (Lv), a sensitive biomarker derived from Paralichthys olivaceus for environmental estrogen, has been established. The immunosensor has a wide linear test range (0.001–1500 ng/mL), a lower limit of detection (LOD, 0.9 pg/mL), excellent sensitivity (26,407.8 CPS/(ng/mL)), and high selectivity and reproducibility for Lv quantification. The results demonstrated that the visible-Fenton is a simple, mild, green, efficient, and general approach to fabricating GQDs, and the fluorescent “ON-OFF” immunosensor is an easy-to-use, time-saving, ultrasensitive, and accurate detection method for weak estrogenic activity.

High fluorescent graphene quantum dots (GQDs) are promising in bioimaging and optoelectronics. In this paper, bright blue fluorescent N-doped GQDs were synthesized using a ultrasonic-assisted hydrothermal method. The morphology, structure, surface chemistry, optical properties, and stability subject to photo-bleaching, temperature, pH and preservation period for the N-GQDs were investigated in detail using various microscopy and spectroscopy techniques. The results showed that the N-GQDs possessed an average size of 2.65 nm, 3.57% N doping, and up to 54% quantum yield (QY). The photoluminescence (PL) spectra of the N-GQDs are excitation dependent when excited in the range of 300–370 nm and excitation independent in the range of 380–500 nm for the core and surface states emission. The N-GQDs showed excellent photo-bleaching resistance and superior photo-stability. At room temperature and in the pH range of 3–8, the fluorescence of the N-GQDs was almost invariable. The N-GQDs can be stably preserved for at least 40 days. The average decay lifetime of the N-GQDs was 2.653 ns, and the radiative and nonradiative decay rate constants were calculated to be 2.04 × 108 s−1 and 1.73 × 108 s−1, respectively. The PL mechanism was qualitatively explained. The N-GQDs was used for cell imaging, and it showed good results, implying great potential applications for bioimaging or biomarking.

A green method was used to synthesize Cu2O@BSA nanoparticles (NPs). The influential factors on the morphologies of NPs were investigated. The result showed that the alkalinity of reactant solution plays an important role. Fourier transform infrared (FTIR) spectroscopy indicated that Cu2+ interacts strongly with O positioned at peptide chain and N in amide of BSA. The formation mechanism of Cu2O@BSA NPs depends on the unfolding of the peptide of BSA proceeds the electrostatic interaction between Cu2+ and BSA. The experimental results are of importance for fabrication of semiconductor NPs by using BSA or other protein as coating agents.

Vitellogenin (Vtg) is a biomarker for environmental estrogens, and its sensitive detection method is vital for the detection of weak estrogenic activity. This study aimed to develop sensitive electrochemical immunosensors for marine medaka (Oryzias melastigma) Vtg based on novel nanomaterials. Firstly, Cu2O-BSA nanoparticles (NPs) with a diameter of 120-150 nm was synthesized, and monoclonal antibody against lipovitellin (anti-Lv mAb) was prepared. Then two simple and efficient label-free immunosensors for the detection of Vtg were established using Cu2O-BSA NPs and gold nanoparticle (Au NPs) as signal amplification elements and anti-Lv mAb as the detection probe. These two immunosensors have good sensitivity, selectivity, reproducibility for Vtg quantification, and are easy to use. Moreover, the BSA/Anti-Lv mAb/Au/Cu2O-BSA/GCE immunosensor exhibited a linear range from 0.128 to 5 x 10(4) pg/mL, with the lowest detection limit (LOD) of 0.09 pg/mL, which is considerably lower than those of the previously reported Vtg detection techniques. Finally, the performance of the immunosensor was evaluated by quantifying Vtg concentrations in plasma of male marine medaka exposed three estrogenic bisphenols. The results demonstrated that the BSA/Anti-Lv mAb/Au/Cu2O-BSA/GCE immunosensor was an easily-operated, ultrasensitive and accurate detection method for weak estrogenic activity.

Fluorescent N-doped carbon nanodots (CNDs) are a type of environmentally friendly nanomaterial that is promising for application in cell imaging and optoelectronics. In this paper, a natural amino acid (l-glutamic acid) was used as a precursor, and two different morphological and structured N-doped carbon quantum dots (CQDs) were synthesized via a one-step ultrasonic-assisted hydrothermal method at 230 and 250 °C. Various microscopy and spectroscopy techniques were employed to characterize the morphology, structure, optical properties, and stability of the CQDs. The results showed that N-CQDs-1 are new CNDs composed of amorphous carbon with a large amount of pyroglutamic acid, and N-CQDs-2 are composed of pure amorphous carbon. The CQDs exhibit excellent optical properties, such as 40.5% quantum yield, strong photobleaching resistance, and superior photostability. Combining the fluorescence lifetimes and radiative and non-radiative decay constants, the photoluminescence mechanism of the CQDs was qualitatively explained. The two CQDs were used for BV2 cell imaging and showed good results, implying the ultrasonic-assisted hydrothermal approach as a facile method to obtain structure- and morphology-controllable N-doped CQDs with prospect for application in cell imaging.

Introduction: Copolymer PBB-T with benzo[1,2-d:4,5-d']bis(thiazole) (BBT) as the accepting unit and benzodithiophene (BDT) as the donor unit is a promising candidate for highperformance non-fullerene polymer solar cells (PSCs). So far optical and dielectric constants of the PBB-T are not fully known. Method: PBB-T was synthesized and thin films of PBB-T were prepared. By using the Kramers-Kronig relations and the transmission spectra of the PBB-T films, the optical and dielectric constants, including in absorption coefficient (α(λ)), extinction coefficient (κ(λ)), refractive index (n(λ)), dielectric constant (ε1(λ),ε2(λ)), band gap (Eg) and mobility of the PBB-T films were calculated and analyzed. Result: At 500 nm, α, κ, n, ε1 and ε2 are 1.65×105 cm-1, 0.46, 1.8163, 3.0 and 1.65 respectively. Eg is 2.111 eV. The hole mobility of PBB-T are 2.41×10-5 cm2 V-1 s-1 and 1.71×10-4 cm2 V-1 s-1 for the as-cast film and for the solvent vapor annealed film respectively. The results show that these optical and dielectric constants of the PBB-T films are almost independent on the thicknesses of the films, indicating our results are reliable. The features of the optical and dielectric constants show the PBB-T films are very promising candidates for high-performance non-fullerene PSCs and potential cut-off filter only permitting red and near-infrared light passing. Conclusion: These results are significant for designing optoelectronic devices related to the PBBT thin films.

Introduction: By using Cu(NO3)2 as precursor and polyvinylpyrrolidone (PVP) as surfactant, nanosheets of Cu2(OH)3NO3, nanowires of Cu(OH)2 or the mixture of the two were prepared under different molar ratios of OH− to Cu2+. Materials and Methods: The crystal structures and morphologies of the products were characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM). Results: When the molar ratio of OH− to Cu2+ in reaction solution is lower than 1.28, pure Cu2(OH)3NO3 nanosheets were obtained. The thickness of one piece of nanosheet is about 167 nm. The Cu2(OH)3NO3 nanosheets consists of two types of crystal structures, monoclinic phase and orthorhombic phase. With increase of the molar ratio of OH− to Cu2+, the monoclinic phase of Cu2(OH)3NO3 was transferred to the orthorhombic phase of Cu2(OH)3NO3. When the molar ratio of OH− to Cu2+ is within 1.28-2.24, the product is the mixture of Cu2(OH)3NO3 nanosheets and Cu(OH)2 nanowires. And when this molar ratio is higher than 2.24, only Cu(OH)2 nanowires were produced. The lengths and the diameters of the Cu(OH)2 nanowires are in the region of 50-250 nm and 10 nm, respectively. Conclusion: The reason of the Cu2(OH)3NO3 nanosheets changing into the Cu(OH)2 nanowires is that the OH− anions replace the NO3 − anions in the layered Cu2(OH)3NO3 nanosheets, which causes the rupture of hydrogen bonds connecting the adjacent layers. The Cu(OH)2 nanowires were not stable and found to become spindled CuO nanosheets in air at room temperature.

Transition-metal nanomaterials are very important to non-enzymatic glucose sensing because of their excellent electrocatalytic ability, good selectivity, the fact that they are not easily interfered with by chloride ion (Cl−), and low cost. However, the linear detection range needs to be expanded. In this paper, Cu2O–bovine serum albumin (BSA) core-shell nanoparticles (NPs) were synthesized for the first time in air at room temperature by a facile and green route. The structure and morphology of Cu2O–BSA NPs were characterized. The as-prepared Cu2O–BSA NPs were used to modify the glassy carbon electrode (GCE) in a Nafion matrix. By using cyclic voltammetry (CV), the influence from scanning speed, concentration of NaOH, and load of Cu2O–BSA NPs for the modified electrodes was probed. Cu2O–BSA NPs showed direct electrocatalytic activity for the oxidation of glucose in 50 mM NaOH solution at 0.6 V. The chronoamperometry result showed this constructing sensor in the detection of glucose with a lowest detection limit of 0.4 μM, a linear detection range up to 10 mM, a high sensitivity of 1144.81 μAmM−1cm−2 and reliable anti-interference property to Cl−, uric acid (UA), ascorbic acid (AA), and acetaminophen (AP). Cu2O–BSA NPs are promising nanostructures for the fabrication of non-enzymatic glucose electrochemical sensing devices.

Till now, optical and dielectric constants of polymer based on poly(benzo[1,2-b:4,5-b’]- dithiophene–thieno [3,4-c]pyrrole-4,6-dione) (PBDTTPD) incorporated into thiophene (PBDTTTPD) have not been systematically investigated. In this work, PBDTTTPD thin film was prepared on ITO glass substrate. Transmittance spectra of ITO and PBDTTTPD films were measured. Based on unconstrained optimization method, the glass was firstly as the substrate, the thickness and the refractive index of the ITO were retrieved. Then the refractive index data of the ITO thin film were added to the PUMA program and the ITO was taken as the new substrate, the thickness, optical and dielectric constants of the PBDTTTPD film were further simulated only via the transmittance spectra. These optical and dielectric parameters are promising useful in design optical devices related to PBDTTTPD polymer.

A new method coupling novel solid-phase extraction (SPE) with inductively coupled plasma-atomic emission spectrometry (ICP-AES) was developed, based on the adsorbent prepared by modifying a strong-coordinating bis-pyrazolyl functional monomer onto mesoporous silica SBA-15. The adsorbent DPP@SBA-15 was characterized by a set of analytical techniques, as well as studied the optimized various experimental parameters such as pH, stripping agent, adsorption capacity and equilibrium adsorption time. This newly developed adsorbent material do exhibit good chemical and mechanical stability, satisfactory adsorption capacity (72.5 mg/g) and high selectivity for Cr(III). Consequently, the DPP@SBA-15 was utilized as SPE adsorbent for adsorption of Cr(III) and determination of Cr(VI). An excellent linearity was shown in the range of 1-20 mu g/mL(-1) (R-2 = 0.9999), and the limit of determination 0.028 mu g/mL(-1). Furthermore, Cr(VI) released from artificial ring was successfully detected and considerable recoveries varying from 97.6 to 103.0% were attained. (C) 2016 Elsevier B.V. All rights reserved.