In this work, bismuth oxide nanoparticles (Bi2O3NPs) are preparation by laser ablation at diverse laser energy 200, 400, 600 and 800 mJ with 100 shots and laser wavelength 1064 nm then deposited on ...porous silicon (PS). X-ray diffraction (XRD) study revealed that Bi2O3NPs is crystalline and belong to α-phase with monoclinic symmetry. Atomic force microscope (AFM) study results for PS showed sponge like structure, and for Bi2O3NPs appears an average diameter of 31.09 nm coordinated in a rod-like shape, are watching and electrical properties are carried out to describe the samples. Fourier Transform Infrared (FTIR) spectra showed the oxidation of PS substrate resulting in the passivating of the surface states and for Bi2O3NPs/PS confirming the presence of Bi-O bond. The electrical properties such as barrier height (ΦB) and ideal factor (n) of the Al/PS/Si/Al and Al/Bi2O3NPs/PS/Si/Al heterojunction were calculated from the current–voltage (I-V) measurements.
Finally, we appeared enhanced effectiveness of Bi2O3NPs/PS photodetectors through a wide domain of wavelengths.
Periodontal disease is a significant burden for oral health, causing progressive and irreversible damage to the support structure of the tooth. This complex structure, the periodontium, is composed ...of interconnected soft and mineralised tissues, posing a challenge for regenerative approaches. Materials combining silicon and lithium are widely studied in periodontal regeneration, as they stimulate bone repair via silicic acid release while providing regenerative stimuli through lithium activation of the Wnt/β-catenin pathway. Yet, existing materials for combined lithium and silicon release have limited control over ion release amounts and kinetics. Porous silicon can provide controlled silicic acid release, inducing osteogenesis to support bone regeneration. Prelithiation, a strategy developed for battery technology, can introduce large, controllable amounts of lithium within porous silicon, but yields a highly reactive material, unsuitable for biomedicine. This work debuts a strategy to lithiate porous silicon nanowires (LipSiNs) which generates a biocompatible and bioresorbable material. LipSiNs incorporate lithium to between 1% and 40% of silicon content, releasing lithium and silicic acid in a tailorable fashion from days to weeks. LipSiNs combine osteogenic, cementogenic and Wnt/β-catenin stimuli to regenerate bone, cementum and periodontal ligament fibres in a murine periodontal defect.
Porous-Silicon/Zinc Oxide (PS-ZnO) nanocomposites can be processed by a combination of electrochemical etching of PS and sol-gel infiltration of ZnO, which leads to complex interfaces of ZnO ...permeated in the PS matrix. In this work, an approach consisting on the determination of transport mechanisms and identification of electroluminescence emission bands from the heterojunction, has been followed to derive the energy band diagram. Charge transport at room temperature has been determined in ITO/PS-ZnO/p+-Si/Al structures through current-voltage characteristics, showing that direct and Fowler-Nordheim (FN) tunneling are the main conduction mechanisms at low and high bias voltages, respectively. White electroluminescence composed of three main bands (~490, ~550 and ~620nm) is observed at forward bias. Emission starts at a threshold voltage of 3.9±0.2V, in coincidence with the change in conduction mechanism from direct to FN tunneling. A band diagram of the device is derived from the emission and transport properties, which is coherent with previous electronic and microstructural properties of the starting n-ZnO and p+-Si.
Ischemic heart disease is the leading cause of death globally. Severe myocardial ischemia results in a massive loss of myocytes and acute myocardial infarction, the endocardium being the most ...vulnerable region. At present, current therapeutic lines only ameliorate modestly the quality of life of these patients. Here, an engineered nanocarrier is reported for targeted drug delivery into the endocardial layer of the left ventricle for cardiac repair. Biodegradable porous silicon (PSi) nanoparticles are functionalized with atrial natriuretic peptide (ANP), which is known to be expressed predominantly in the endocardium of the failing heart. The ANP–PSi nanoparticles exhibit improved colloidal stability and enhanced cellular interactions with cardiomyocytes and non‐myocytes with minimal toxicity. After confirmation of good retention of the radioisotope 111‐Indium in relevant physiological buffers over 4 h, in vivo single‐photon emission computed tomography (SPECT/CT) imaging and autoradiography demonstrate increased accumulation of ANP–PSi nanoparticles in the ischemic heart, particularly in the endocardial layer of the left ventricle. Moreover, ANP–PSi nanoparticles loaded with a novel cardioprotective small molecule attenuate hypertrophic signaling in the endocardium, demonstrating cardioprotective potential. These results provide unique insights into the development of nanotherapies targeted to the injured region of the myocardium.
Coronary heart disease is the main cause of death worldwide, the endocardium being the most vulnerable region for myocardial ischemia. Here, the development of a multifunctional nanoparticle with cardioprotective potential is reported, which selectively targets the endocardial layer of the left ventricle upon intravenous injection and delivers a drug molecule for modulating hypertrophic signaling.
Engineering surfaces with excellent wicking properties is of critical importance to a wide range of applications. Here, we report a facile method to create superhydrophilic nanoporous micropillared ...surfaces of silicon and their applicability to superwicking. Nanopores with a good control of the pore depth are realized over the entire surface of three-dimensional micropillar structures by electrochemical etching in hydrofluoric acid. After rinsing in hydrogen peroxide, the nanoporous micropillared surface shows superhydrophilicity with the superwicking effect. The entire spreading process of a water droplet on the superhydrophilic nanoporous micropillared surface is completed in less than 50 ms, with an average velocity of 91.2 mm/s, which is significantly faster than the other wicking surfaces reported. Owing to the presence of nanopores on the micropillar array, the wicking dynamics is distinct from the surfaces decorated only by micropillar arrays. The spreading dynamics of a water droplet shows two distinct processes simultaneously, including the capillary penetration between micropillars and the capillary imbibition into the nanopore’s interior. The wicking dynamics can be described by the two stages separated by the time when the contact line starts to recede. The transition between the two wicking regimes is due to the increasing effect of the imbibition of the bulk droplet by the nanopores. While a similar transition of the wicking dynamics is shown on the surfaces with different pore depths, the nanopore structure with a greater depth causes a greater amount of imbibition to slow down the spreading and promote superwicking.
•A cost-effective and simple to use colorimetric sensing protocol is proposed.•No need for special light sources, neither costly microscopes or plate readers.•Porous silicon microcavities are used to ...detect 10 fg ml−1 anti-histones in serum.•The RGB analysis of the color formed in diffuse light enables to quantify molecules.•Use of photonic substrates amplify 100 x detection sensitivity compared to ELISA.
Cost-effective health care technologies for detection of disease biomarkers at ultralow concentrations can significantly improve the quality of life in resource-constrained countries. However, current techniques require expensive instruments, complex conjugation protocols and tedious laboratory procedures that may not be affordable for the major part of the world population. Here, we propose to sidestep the problem by establishing a simple, relatively inexpensive sensing method employing a photonic substrate, a material affinity peptide, and a smart phone CCD detector to achieve detection of clinically relevant proteins in serum at concentrations much lower than standard enzyme-linked immunosorbent assay (ELISA). Easy to process porous silicon (PSi) microcavities were employed as substrates that provide a three-dimensionality, large surface area, and convenient light enhancement properties for molecular detection. Anti-histone H2 B antibodies and biomarkers of severe illnesses are detected in whole serum at concentrations as low as 10 fg mL−1 by using the proposed PSi- ELISA protocol. Due to its easy use, cost effectiveness and high sensitivity, the proposed method has potential large-scale applications in ultrasensitive sensing of different other clinically relevant molecules for early stage diagnostics.
Porous silicon (PSi) particles have been studied for the effects they elicit in Caco-2 and RAW 264.7 macrophage cells in terms of toxicity, oxidative stress, and inflammatory response. The most ...suitable particles were then functionalized with a novel 18F label to assess their biodistribution after enteral and parenteral administration in a rat model. The results show that thermally hydrocarbonized porous silicon (THCPSi) nanoparticles did not induce any significant toxicity, oxidative stress, or inflammatory response in Caco-2 and RAW 264.7 macrophage cells. Fluorescently labeled nanoparticles were associated with the cells surface but were not extensively internalized. Biodistribution studies in rats using novel 18F-labeled THCPSi nanoparticles demonstrated that the particles passed intact through the gastrointestinal tract after oral administration and were also not absorbed from a subcutaneous deposit. After intravenous administration, the particles were found mainly in the liver and spleen, indicating rapid removal from the circulation. Overall, these silicon-based nanosystems exhibit excellent in vivo stability, low cytotoxicity, and nonimmunogenic profiles, ideal for oral drug delivery purposes.
Porous silicon has been utilized within a wide spectrum of industries, as well as being used in basic research for engineering and biomedical fields. Recently, surface modification methods have been ...constantly coming under the spotlight, mostly in regard to maximizing its purpose of use. Within this review, we will introduce porous silicon, the experimentation preparatory methods, the properties of the surface of porous silicon, and both more conventional as well as newly developed surface modification methods that have assisted in attempting to overcome the many drawbacks we see in the existing methods. The main aim of this review is to highlight and give useful insight into improving the properties of porous silicon, and create a focused description of the surface modification methods.
•First use of graphene (GR)-quantum-dots interlayer in GR/porous Si (PSi) solar cells.•Maximum efficiency is 13.66%, highest ever achieved in GR/PSi solar cells.•The efficiency is maintained at 84% ...even in air for 30 days.
Formation of Porous Si (PSi) enhances the light absorption of Si thanks to the increased surface-to-volume ratio, useful for improving the power conversion efficiency (PCE) of Si-based solar cells. Here, we first employ graphene quantum dots (GQDs) as an interfacial layer for better band alignment at the graphene (GR) transparent conductive electrode (TCE)/PSi interface. The PCE exhibits a maximum of 13.66%, highest ever achieved in GR/PSi solar cells, by doping the GR TCE and passivating the Si back surface in addition to the GQDs interfacial layer. The use of the interfacial and the passivating layers results in the reduction of the carrier recombination at the GR TCE/PSi and Si/cathode interfaces, respectively. The cell also shows excellent long-term stability by maintaining 84% of its original PCE even in air for 30 days.
In this paper, based on the gray value change of reflected light image of porous silicon (PSi) Bragg mirror, a fast and simple biological detection method is proposed. In this method, CdSe/ZnS ...quantum dots (QDs) are used as markers for refractive index amplification, and digital image method is used for detection. The detection light has the same wavelength as the lowest reflectivity of the edge of the Bragg mirror, and the reflected light radiated on the surface of the Bragg mirror is received by the detector. The theoretical simulation results show that the intensity of the reflected light increases with the increase of the refractive index caused by the biological reaction. According to the experimental results, the average gray value variation increases with the increase of the target DNA concentration and becomes a linear relationship in a certain range. Based on this method, the DNA detection limit is 20.74 pM. The method is low-cost, has a short detection time and can be used in the detection of biosensor microarray.
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