Correction: Surface modification of medical grade biomaterials by using a low-temperature-processed dual functional Ag-TiO2 coating for preventing biofilm formation.

Correction for 'Surface modification of medical grade biomaterials by using a low-temperature-processed dual functional Ag-TiO2 coating for preventing biofilm formation' by Lipi Pradhan et al., J. Mater. Chem. B, 2024, https://doi.org/10.1039/D4TB00701H.

Surface modification of medical grade biomaterials by using a low-temperature-processed dual functional Ag-TiO2 coating for preventing biofilm formation.

Biofilm development in medical devices is considered the major virulence component that leads to increased mortality and morbidity among patients. Removing a biofilm once formed is challenging and frequently results in persistent infections. Many current antibiofilm coating strategies involve harsh conditions causing damage to the surface of the medical devices. To address the issue of bacterial attachment in medical devices, we propose a novel antibacterial surface modification approach. In this paper, we developed a novel low-temperature based solution-processed approach to deposit silver nanoparticles (Ag NPs) inside a titanium oxide (TiO2) matrix to obtain a Ag-TiO2 nanoparticle coating. The low temperature (120 °C)-based UV annealed drop cast method is novel and ensures no surface damage to the medical devices. Various medical-grade biomaterials were then coated using Ag-TiO2 to modify the surface of the materials. Several studies were performed to observe the antibacterial and antibiofilm properties of Ag-TiO2-coated medical devices and biomaterials. Moreover, the Ag-TiO2 NPs did not show any skin irritation in rats and showed biocompatibility in the chicken egg model. This study indicates that Ag-TiO2 coating has promising potential for healthcare applications to combat microbial infection and biofilm formation.

Emulating Low-Power Synaptic Plasticity in a Solution-Processed Oxide-Based Long Retention Memory Transistor with High Learning Accuracy.

The exploration of synaptic plasticity in metal-oxide-based ferroelectric thin-film transistors has been limited. As a perovskite ferroelectric material, LiNbO3 is widely studied; but its potential use as a neuromorphic device, like synaptic transistors, has not been realized. In this study, a solution-processed ferroelectric thin-film transistor (FeTFT) with an alternating layer of LiNbO3 and Li5AlO4 as a gate dielectric has been fabricated. This configuration reduces the depolarization field by leveraging the large ionic polarization of Li+ ions in the Li5AlO4 layer, while the wide bandgap helps mitigate the leakage current. FeTFT exhibits impressive transistor performance, including a saturation mobility of 0.478 cm2V-1 s-1, an on/off ratio of 3.08 × 103, and a low trap-state density of 1.3 × 1013 cm-2. Moreover, the device demonstrates good memory retention, retaining information for nearly 1 day. It successfully emulates synaptic plasticity, specifically short-term plasticity and long-term plasticity. Besides, a 94% training accuracy has been achieved through artificial neural network simulation. Notably, the FeTFT consumes minimal power, with energy consumption of approximately 3.09 nJ per synaptic event, which is remarkably low compared to other reported solution-processed FeTFT devices.

Screening of Lithium Substituted Ag-TiO2 Nanoparticle Coating for Antibiofilm Application.

Bacterial infections and biofilm growth are common mishaps associated with medical devices, and they contribute significantly to ill health and mortality. Removal of bacterial deposition from these devices is a major challenge, resulting in an immediate necessity for developing antibacterial coatings on the surfaces of medical implants. In this context, we developed an innovative coating strategy that can operate at low temperatures (80 °C) and preserve the devices' integrity and functionality. An innovative Ag-TiO2 based coating was developed by ion exchange between silver nitrate (AgNO3) and lithium titanate (Li4Ti5O12) on glass substrates for different periods, ranging from 10 to 60 min. The differently coated samples were tested for their antibacterial and antibiofilm efficacy.

High-Performance Low-Voltage Thin-Film Transistors: Experimental and Simulation Validation of Atmospheric Pressure Plasma-Assisted Li5AlO4 Metal Oxide Solution Processing.

Metal oxide materials processed using solution methods have garnered significant attention due to their ability to efficiently and affordably create transparent insulating layers or active channel layers on various substrates for thin-film transistors (TFTs) used in modern electronics. The key properties of TFTs largely depend on how charge carriers behave near the thin layer at the semiconductor and dielectric interface. Effectively controlling these characteristics offers a straightforward yet effective approach to enhancing device performance. In this study, we propose a novel strategy utilizing atmospheric pressure plasma (APP) treatment to modulate the electrical properties of dielectric thin films and the interfaces between dielectric and semiconductor layers in TFTs processed by using solution methods. Through APP exposure, significant improvements in key TFT parameters were achieved for solution-processed TFTs. Interface states have been reduced from 1013 to 1011 cm-2, and the on/off current ratio has increased from 103 to 106 while maintaining a high field-effect mobility of 34 cm2 V-1 s-1. Additionally, UV-visible spectroscopy and X-ray analysis have confirmed the effectiveness of APP treatment in controlling interface states and traps, leading to overall performance enhancements in the TFTs. Furthermore, our experimental findings have been systematically validated using technology computer-aided design (TCAD) simulations of fabricated TFTs.

Coexistence of Electrochromism and Bipolar Nonvolatile Memory in a Single Viologen.

Viologens are fascinating redox-active organic compounds that have been widely explored in electrochromic devices (ECDs). However, the combination of electrochromic and resistive random-access memory in a single viologen remains unexplored. We report the coexistence of bistate electrochromic and single-resistor (1R) memory functions in a novel viologen. A high-performance electrochromic function is achieved by combining viologen (BzV2+2PF6) with polythiophene (P3HT), enabling a "push-pull" electronic effect due to the efficient intermolecular charge transfer in response to an applied bias. The ECDs show high coloration efficiency (ca. 1150 ± 10 cm2 C-1), subsecond switching time, good cycle stability (>103 switching cycles), and low-bias operation (±1.5 V). The ECDs require low power for switching the color states (55 µW cm-2 for magenta and 141 µW cm-2 for blue color). The random-access memory devices (p+2-Si/BzV2+2PF6/Al) exhibit distinct low and high resistive states with an ON/OFF ratio of ∼103, bipolar and nonvolatile characteristics that manifest good performances, and "Write"-"Read"-"Erase" (WRE) functions. The charge conduction mechanism of the RRAM device is elucidated by the Poole-Frenkel model where SET and RESET states arise at a low transition voltage (VT = ±1.7 V). Device statistics and performance parameters for both electrochromic and memory devices are compared with the literature data. Our findings on electrochromism and nonvolatile memory originated in the same viologen could boost the development of multifunctional, smart, wearable, flexible, and low-cost optoelectronic devices.

Solvent Evaporation Induced Large-Scale Synthesis of Cs4PbBr6 and CsPbBr3 Microcrystals: Optical Properties and Backlight Application for LEDs.

The contemporary work focuses on embossing the emissive nature of lead halide perovskite materials, specifically Cs4PbBr6 microcrystal powder prepared via single step bulk recrystallization method followed by the solvent evaporation route from gram to kilogram scale. The X-ray diffraction pattern confirms the formation of phase pure Cs4PbBr6 with a goodness of fit value of 1.51 calculated from Rietveld refinement and the fluorophore powder manifesting an intrinsic band gap of 3.76 eV. The experimental yield of 99.4% indicates the absence of any unreacted precursors. The fabricated flexible, free-standing Cs4PbBr6@PMMA film encompassed better moisture stability without undergoing phase transitions for 400 days. The temperature-dependent photoluminescence spectra denote that 51% of the intensity was retained when cooled back to room temperature after heating it till 180 °C. Moisture studies at two extreme humidity conditions also reveal the appreciable stability of the fluorophore film against moisture. The stability studies with respect to UV irradiation substantiate that the film retained its stability even after exposing it continuously to UV radiation for seven days. The outstanding optical properties of these microcrystals, owing to the higher exciton binding energy, make them a promising candidate as excellent fluorophores for color conversion, backlight, and light-emitting applications. The Cs4PbBr6@PMMA film was employed as the top cover of a commercial blue LED, producing a robust green emission which revealed its possible application as a phosphor material.

Ingenious Fabrication of Ag-Filled Porous Anodic Alumina Films as Powerful SERS Substrates for Efficient Detection of Biological and Organic Molecules.

Surface-enhanced Raman scattering (SERS) has been widely used to effectively detect various biological and organic molecules. This detection method needs analytes adsorbed onto a specific metal nanostructure, e.g., Ag-nanoparticles. A substrate containing such a structure (called SERS substrate) is user-friendly for people implementing the adsorption and subsequent SERS detection. Here, we report on powerful SERS substrates based on efficient fabrication of Ag-filled anodic aluminum oxide (AAO) films. The films contain many nanopores with small as-grown inter-pore gap of 15 nm. The substrates are created by electrochemically depositing silver into nanopores without an additional pore widening process, which is usually needed for conventional two-step AAO fabrication. The created substrates contain well-separated Ag-nanoparticles with quite a small inter-particle gap and a high number density (2.5 × 1010 cm-2). We use one-step anodization together with omitting additional pore widening to improve the throughput of substrate fabrication. Such substrates provide a low concentration detection limit of 10-11 M and high SERS enhancement factor of 1 × 106 for rhodamine 6G (R6G). The effective detection of biological and organic molecules by the substrate is demonstrated with analytes of adenine, glucose, R6G, eosin Y, and methylene blue. These results allow us to take one step further toward the successful commercialization of AAO-based SERS substrates.

Resolving Cross-Sensitivity Effect in Fluorescence Quenching for Simultaneously Sensing Oxygen and Ammonia Concentrations by an Optical Dual Gas Sensor.

Simultaneous sensing of multiple gases by a single fluorescent-based gas sensor is of utmost importance for practical applications. Such sensing is strongly hindered by cross-sensitivity effects. In this study, we propose a novel analysis method to ameliorate such hindrance. The trial sensor used here was fabricated by coating platinum(II) meso-tetrakis(pentafluorophenyl)porphyrin (PtTFPP) and eosin-Y dye molecules on both sides of a filter paper for sensing O2 and NH3 gases simultaneously. The fluorescent peak intensities of the dyes can be quenched by the analytes and this phenomenon is used to identify the gas concentrations. Ideally, each dye is only sensitive to one gas species. However, the fluorescent peak related to O2 sensing is also quenched by NH3 and vice versa. Such cross-sensitivity strongly hinders gas concentration detection. Therefore, we have studied this cross-sensitivity effect systematically and thus proposed a new analysis method for accurate estimation of gas concentration. Comparing with a traditional method (neglecting cross-sensitivity), this analysis improves O2-detection error from -11.4% ± 34.3% to 2.0% ± 10.2% in a mixed background of NH3 and N2.

One-dimensional ZnO nanostructure arrays: synthesis and characterization.

One-dimensional ZnO nanostructure arrays such as nanowires, nanonails, and nanotrees, have been synthesized by oxygen assisted thermal evaporation of metallic zinc on a quartz substrate over a large area. Morphological evolution of ZnO nanostructures at different time scales and different positions of the substrates have been studied by electron microscopy. A self-catalyzed vapor-liquid-solid (VLS) process is believed to be responsible for the nucleation and subsequently a vapor-solid process is operative for further longitudinal growth. The photoluminescence spectrum showed a weak UV and a broad green emission peak at 3.25 and 2.49 eV, respectively. The latter was attributed to the presence of zinc interstitial defects. Electrical resistivity as a function of temperature showed activated mechanisms to be present. The electrical response of the ZnO nanonail arrays to different gases (CO, NO2, and H2S) indicated that there could be possible application as gas sensors for this material.