Erythrocyte-Mimicking Nanovesicle Targeting Porphyromonas gingivalis for Periodontitis.

Porphyromonas gingivalis has been demonstrated to have the strongest association with periodontitis. Within the host, P. gingivalis relies on acquiring iron and heme through the aggregation and lysis of erythrocytes, which are important factors in the growth and virulence of P. gingivalis. Additionally, the excess obtained heme is deposited on the surface of P. gingivalis, protecting the cells from oxidative damage. Based on these biological properties of the interaction between P. gingivalis and erythrocytes, this study developed an erythrocyte membrane nanovesicle loaded with gallium porphyrins to mimic erythrocytes. The nanovesicle can target and adhere with P. gingivalis precisely, being lysed and utilized by P. gingivalis as erythrocytes. Ingested gallium porphyrin replaces iron porphyrin in P. gingivalis, causing intracellular metabolic disruption. Deposited porphyrin generates a large amount of reactive oxygen species (ROS) under blue light, causing oxidative damage, and its lethality is enhanced by bacterial metabolic disruption, synergistically killing P. gingivalis. Our results demonstrate that this strategy can target and inhibit P. gingivalis, reduce its invasion of epithelial cells, and alleviate the progression of periodontitis.

Selective detection of food contaminants using engineered gallium-organic frameworks with MD and metadynamics simulations.

The exclusion mechanism of food contaminants such as bisphenol A (BPA), Flavonoids (FLA), and Goitrin (GOI) onto the novel gallium-metal organic framework (MOF) and functionalized MOF with oxalamide group (MOF-OX) is evaluated by utilizing molecular dynamics (MD) and Metadynamics simulations. The atoms in molecules (AIM) analysis detected different types of atomic interactions between contaminant molecules and substrates. To assess this procedure, a range of descriptors including interaction energies, root mean square displacement, radial distribution function (RDF), density, hydrogen bond count (HB), and contact numbers are examined across the simulation trajectories. The most important elements in the stability of the systems under examination are found to be stacking π-π and HB interactions. It was confirmed by a significant value of total interaction energy for BPA/MOF-OX (- 338.21 kJ mol-1) and BPA/MOF (- 389.95 kJ mol-1) complexes. Evaluation of interaction energies reveals that L-J interaction plays an essential role in the adsorption of food contaminants on the substrates. The free energy values for the stability systems of BPA/MOF and BPA/MOF-OX complexes at their global minima reached about BPA/MOF = - 254.29 kJ mol-1 and BPA/MOF-OX = - 187.62 kJ mol-1, respectively. Nevertheless, this work provides a new strategy for the preparation of a new hierarchical tree-dimensional of the Ga-MOF hybrid material for the adsorption and exclusion of food contaminates and their effect on human health.

Orally administrated liquid metal agents for inflammation-targeted alleviation of inflammatory bowel diseases.

Rapid drug clearance and off-target effects of therapeutic drugs can induce low bioavailability and systemic side effects and gravely restrict the therapeutic effects of inflammatory bowel diseases (IBDs). Here, we propose an amplifying targeting strategy based on orally administered gallium (Ga)-based liquid metal (LM) nano-agents to efficiently eliminate reactive oxygen and nitrogen species (RONS) and modulate the dysregulated microbiome for remission of IBDs. Taking advantage of the favorable adhesive activity and coordination ability of polyphenol structure, epigallocatechin gallate (EGCG) is applied to encapsulate LM to construct the formulations (LM-EGCG). After adhering to the inflamed tissue, EGCG not only eliminates RONS but also captures the dissociated Ga to form EGCG-Ga complexes for enhancive accumulation. The detained composites protect the intestinal barrier and modulate gut microbiota for restoring the disordered enteral microenvironment, thereby relieving IBDs. Unexpectedly, LM-EGCG markedly decreases the Escherichia_Shigella populations while augmenting the abundance of Akkermansia and Bifidobacterium, resulting in favorable therapeutic effects against the dextran sulfate sodium-induced colitis.

Highly stretchable, self-healing, antibacterial, conductive, and amylopectin-enhanced hydrogels with gallium droplets loading as strain sensors.

In this study, we address the challenge of developing highly conductive hydrogels with enhanced stretchability for use in wearable sensors, which are critical for the precise detection of human motion and subtle physiological strains. Our novel approach utilizes amylopectin, a biopolymer, for the uniform integration of liquid metal gallium into the hydrogel matrix. This integration results in a conductive hydrogel characterized by remarkable elasticity (up to 7100 % extensibility) and superior electrical conductance (Gauge Factor = 31.4), coupled with a minimal detection limit of less than 0.1 % and exceptional durability over 5000 cycles. The hydrogel demonstrates significant antibacterial activity, inhibiting microbial growth in moist environments, thus enhancing its applicability in medical settings. Employing a synthesis process that involves ambient condition polymerization of acrylic acid, facilitated by a hydrophobic associative framework, this hydrogel stands out for its rapid gelation and robust mechanical properties. The potential applications of this hydrogel extend beyond wearable sensors, promising advancements in human-computer interaction through technologies like wireless actuation of robotic systems. This study not only introduces a viable material for current wearable technologies but also sets a foundation for future innovations in bio-compatible sensors and interactive devices.

Evaluating spectral performance for quantitative contrast-enhanced breast CT with a GaAs based photon counting detector: a simulation approach.

Quantitative contrast-enhanced breast computed tomography (CT) has the potential to improve the diagnosis and management of breast cancer. Traditional CT methods using energy-integrated detectors and dual-exposure images with different incident spectra for material discrimination can increase patient radiation dose and be susceptible to motion artifacts and spectral resolution loss. Photon Counting Detectors (PCDs) offer a promising alternative approach, enabling acquisition of multiple energy levels in a single exposure and potentially better energy resolution. Gallium arsenide (GaAs) is particularly promising for breast PCD-CT due to its high quantum efficiency and reduction of fluorescence x-rays escaping the pixel within the breast imaging energy range. In this study, the spectral performance of a GaAs PCD for quantitative iodine contrast-enhanced breast CT was evaluated. A GaAs detector with a pixel size of 100µm, a thickness of 500µm was simulated. Simulations were performed using cylindrical phantoms of varying diameters (10 cm, 12 cm, and 16 cm) with different concentrations and locations of iodine inserts, using incident spectra of 50, 55, and 60 kVp with 2 mm of added aluminum filtration and and a mean glandular dose of 10 mGy. We accounted for the effects of beam hardening and energy detector response using TIGRE CT open-source software and the publicly available Photon Counting Toolkit (PcTK). Material-specific images of the breast phantom were produced using both projection and image-based material decomposition methods, and iodine component images were used to estimate iodine intake. Accuracy and precision of the proposed methods for estimating iodine concentration in breast CT images were assessed for different material decomposition methods, incident spectra, and breast phantom thicknesses. The results showed that both the beam hardening effect and imperfection in the detector response had a significant impact on performance in terms of Root Mean Squared Error (RMSE), precision, and accuracy of estimating iodine intake in the breast. Furthermore, the study demonstrated the effectiveness of both material decomposition methods in making accurate and precise iodine concentration predictions using a GaAs-based photon counting breast CT system, with better performance when applying the projection-based material decomposition approach. The study highlights the potential of GaAs-based photon counting breast CT systems as viable alternatives to traditional imaging methods in terms of material decomposition and iodine concentration estimation, and proposes phantoms and figures of merit to assess their performance.

Effect of 60Co gamma irradiation on hydrothermally synthesized Ga2O3-Tio2 nanocomposites.

The effect of 60Co gamma irradiation on gallium oxide and titanium oxide (Ga2O3-TiO2) nanocomposites are investigated in the present study. The Ga2O3-TiO2 nanocomposite was synthesized by hydrothermal method at 120°C. The precursors for the synthesis consist of gallium nitrate anhydrous and titanium trichloride along with sodium hydroxide to achieve the pH of 9. The synthesized Ga2O3-TiO2 was subjected to 60Co gamma irradiation for different doses such as 25, 50 and 75 kGy. The morphological, optical and microstructural characteristics were studied using scanning electron microscopy, UV-Visible spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy, respectively. The results shows that the gamma irradiation induces significant changes in the Ga2O3-TiO2 microstructure and there is increase in the grain size and bandgap of the nanocomposites.

Quantitative evaluation of 67Ga-citrate scintigraphy in the management of nephritis.

In 67Ga-citrate scintigraphy (Ga-S), visual assessment is used by evaluating renal-uptake comparison with liver and spine and is simple and objective. We adopted the standardized uptake value (SUV) for 67Ga-citrate and proposed two quantitative indices, active nephritis volume (ANV) and total nephritis uptake (TNU). This study clarified the utility of new Ga-S-based quantitative indices in nephritis management. Before SUV measurement, the Becquerel calibration factor of 67Ga-citrate was obtained using a phantom experiment. Seventy patients who underwent SPECT/CT imaging were studied. SUV, ANV, and TNU were calculated using a quantitative analysis software for bone SPECT. SUVmean, ANV, and TNU were analyzed using the (1) threshold method (set 40%) and constant-value method for (2) vertebral SUVmax, and (3) vertebral SUVmean. ROC analysis was used to evaluate SUV, ANV, and TNU diagnostic abilities to distinguish nephritis presence and absence as well as interstitial nephritis (IN) and non-IN. The area under the curve (AUC) for nephritis presence or absence had a good value (0.80) for SUVmean (1), ANV (3), and TNU (3). The AUC for differentiation between IN and non-IN groups had a good value (0.80) for SUVmean (1). Thus, the new Ga-S-based quantitative indices were useful to evaluate nephritis and distinguish IN and non-IN.

Melatonin-loaded mesoporous zinc- and gallium-doped hydroxyapatite nanoparticles to control infection and bone repair.

Effective treatment of infected bone defects resulting from multi-drug resistant bacteria (MDR) has emerged as a significant clinical challenge, highlighting the pressing demand for potent antibacterial bone graft substitutes. Mesoporous nanoparticles have been introduced as a promising class of biomaterials offering significant properties for treating bone infections. Herein, we synthesize antibacterial mesoporous hydroxyapatite substituted with zinc and gallium (Zn-Ga:mHA) nanoparticles using a facile sol-gel method. The resulting mesoporous nanoparticles are applied for the controlled release of melatonin (Mel). Zn-Ga:mHA nanoparticles with an average particle size of 36 ± 3 nm and pore size of 10.6 ± 0.4 nm reveal a Mel loading efficiency of 58 ± 1%. Results show that 50% of Mel is released within 20 h and its long-term release is recorded up to 50 h. The Zn-Ga:mHA nanoparticles exhibit highly effective antibacterial performance as reflected by a 19 ± 1% and 8 ± 2% viability reduction in Escherichia coli and Staphylococcus bacteria, respectively. Noticeably, Mel-loaded Zn-Ga:mHA nanoparticles are also cytocompatible and stimulate in vitro osteogenic differentiation of human mesenchymal stem cells (hMSCs) without any osteoinductive factor. In vivo studies in a rabbit skull also show significant regeneration of bone during 14 days. In summary, Mel-loaded Zn-Ga:mHA nanoparticles provide great potential as an antibacterial and osteogenic component in bone substitutes like hydrogels, scaffolds, and coatings.

Solution studies, synthesis and antibacterial activity of Ga(III) complexes with bis-kojate derivatives.

Given the recognized major problem of microbial drug resistance for human health, new metal-based drugs have been currently explored for their antimicrobial properties, including gallium-based compounds as potential metallophores that could perturb Fe's interactions with proteins. Herein we have designed and synthesized two bis-kojate ligands (named L4 and L6) and studied their Ga(III) complexes for their physico-chemical and biological properties. In particular a detailed study of their complexation properties in aqueous solution, showed equilibrium models with formation of quite stable dinuclear 2:3 metal:ligand complexes, though with different stability. Solid state complexes were also prepared and characterized and complementary DFT studies indicated that [Ga2(L4)3] complex, with higher stability, seems to adopt a three-ligand bridging conformation, while that for L6 adopt a one ligand bridging conformation. Preliminary investigation of the antibacterial activity of these gallium complexes showed antipseudomonal activity, which appeared higher for the complex with L4, a feature of potential interest for the scientific community.

A win-win platform: Stabilized black phosphorous nanosheets loading gallium ions for enhancing the healing of bacterial-infected wounds through synergistic antibacterial approaches.

Bacterial infection is the most common complication in wound healing, highlighting an urgent need for the development of innovative antibacterial technologies and treatments to address the growing threats posed by bacterial infections. Black phosphorus nanosheets (BPNSs), as a promising two-dimensional nanomaterial, have been utilized in treating infected wounds. However, BP's limited stability restricts its application. In this study, we enhance BP's stability and its antibacterial properties by anchoring gallium ions (Ga3+) onto BP's surface, creating a novel antibacterial platform. This modification reduces BP's electron density and enhances its antibacterial capabilities through a synergistic effect. Under near-infrared (NIR) irradiation, the BP/Ga3+ combination exerts antibacterial effects via photothermal therapy (PTT) and photodynamic therapy (PDT), while also releasing Ga3+. The Ga3+ employ a 'Trojan horse strategy' to disrupt iron metabolism, significantly boosting the antibacterial efficacy of the complex. This innovative material offers a viable alternative to antibiotics and holds significant promise for treating infected wounds and aiding skin reconstruction.

Ultrasound-responsive gallium protoporphyrin and oxygen loaded perfluoropentane nanodroplets for effective sonodynamic therapy of implant infections.

Implant infections are severe complications in clinical treatment, which often accompany the formation of bacterial biofilms with high antibiotic resistance. Sonodynamic therapy (SDT) is an antibiotic-free method that can generate reactive oxygen species (ROS) to kill bacteria under ultrasound (US) treatment. However, the extracellular polymeric substances (EPS) barrier of bacterial biofilms and the hypoxic microenvironment significantly limit the antibiofilm activity of SDT. In this study, lipid-shelled perfluoropentane (PFP) nanodroplets loaded with gallium protoporphyrin IX (GaPPIX) and oxygen (O2) (LPGO NDs) were developed for the treatment of implant infections. Under US stimulation, LPGO NDs undergo the cavitation effect and disrupt the biofilm structure like bombs due to liquid-gas phase transition. Meanwhile, the LPGO NDs release O2 and GaPPIX upon US stimulation. The released O2 can alleviate the hypoxic microenvironment in the biofilm and enhance the ROS formation by GaPPIX for enhanced bacterial killing. In vivo experimental results demonstrate that the LPGO NDs can efficiently treat implant infections of methicillin-resistant Staphylococcus aureus (MRSA) in a mouse model by disrupting the biofilm structure, alleviating hypoxia, and enhancing bacterial killing by SDT. Therefore, this work provides a new multifunctional sonosensitizer to overcome the limitations of SDT for treating implant infections.

MgCa-Based Alloys Modified with Zn- and Ga-Doped CaP Coatings Lead to Controlled Degradation and Enhanced Bone Formation in a Sheep Cranium Defect Model.

Mg-based biodegradable metallic implants are gaining increased attraction for applications in orthopedics and dentistry. However, their current applications are hampered by their high rate of corrosion, degradation, and rapid release of ions and gas bubbles into the physiological medium. The aim of the present study is to investigate the osteogenic and angiogenic potential of coated Mg-based implants in a sheep cranial defect model. Although their osteogenic potential was studied to some extent, their potential to regenerate vascularized bone formation was not studied in detail. We have studied the potential of magnesium-calcium (MgCa)-based alloys modified with zinc (Zn)- or gallium (Ga)-doped calcium phosphate (CaP) coatings as a strategy to control their degradation rate while enhancing bone regeneration capacity. MgCa and its implants with CaP coatings (MgCa/CaP) as undoped or as doped with Zn or Ga (MgCa/CaP + Zn and MgCa/CaP + Ga, respectively) were implanted in bone defects created in the sheep cranium. MgCa implants degraded faster than the others at 4 weeks postop and the weight loss was ca. 50%, while it was ca. 15% for MgCa/CaP and <10% in the presence of Zn and Ga with CaP coating. Scanning electron microscopy (SEM) analysis of the implant surfaces also revealed that the MgCa implants had the largest degree of structural breakdown of all the groups. Radiological evaluation revealed that surface modification with CaP to the MgCa implants induced better bone regeneration within the defects as well as the enhancement of bone-implant surface integration. Bone volume (%) within the defect was ca. 25% in the case of MgCa/CaP + Ga, while it was around 15% for undoped MgCa group upon micro-CT evaluation. This >1.5-fold increase in bone regeneration for MgCa/CaP + Ga implant was also observed in the histopathological examination of the H&E- and Masson's trichrome-stained sections. Immunohistochemical analysis of the bone regeneration (antiosteopontin) and neovascularization (anti-CD31) at the defect sites revealed >2-fold increase in the expression of the markers in both Ga- and Zn-doped, CaP-coated implants. Zn-doped implants further presented low inflammatory reaction, notable bone regeneration, and neovascularization among all the implant groups. These findings indicated that Ga- and Zn-doped CaP coating is an important strategy to control the degradation rate as well as to achieve enhanced bone regeneration capacity of the implants made of Mg-based alloys.

Highly integrated automatic injection terahertz microfluidic biosensor based on metasurface and LT-GaAs photoconductive antenna.

In this paper, a highly integrated terahertz (THz) biosensor is proposed and implemented, which pioneered the preparation of low-temperature gallium arsenide (LT-GaAs) thin film photoconductive antenna (PCA) on the sensor for direct generation and detection of THz waves, simplifying complex terahertz time-domain spectroscopy (THz-TDS) systems. A latch type metasurface is deposited in the detection region to produce a resonance absorption peak at 0.6 THz that is independent of polarisation. Microfluidics is utilised and automatic injection is incorporated to mitigate the experimental effects of hydrogen bond absorption of THz waves in aqueous-based environment. Additionally, cell damage is minimised by regulating the cell flow rate. The biosensor was utilised to detect the concentration of three distinct sizes of bacteria with successful results. The assay was executed as a proof of concept to detect two distinct types of breast cancer cells. Based on the experimental findings, it has been observed that the amplitude and blueshift of the resonance absorption peaks have the ability to identify and differentiate various cancer cell types. The findings of this study introduce a novel approach for developing microfluidic THz metasurface biosensors that possess exceptional levels of integration, sensitivity, and rapid label-free detection capabilities.

Gallium-containing mesoporous nanoparticles influence in-vitro osteogenic and osteoclastic activity.

Mesoporous silica nanoparticles were synthesized using a microemulsion-assisted sol-gel method, and calcium, gallium or a combination of both, were used as dopants. The influence of these metallic ions on the physicochemical properties of the nanoparticles was investigated by scanning and transmission electron microscopy, as well as N2 adsorption-desorption methods. The presence of calcium had a significant impact on the morphology and textural features of the nanoparticles. The addition of calcium increased the average diameter of the nanoparticles from 80 nm to 150 nm, while decreasing their specific surface area from 972 m2/g to 344 m2/g. The nanoparticles of all compositions were spheroidal, with a disordered mesoporous structure. An ion release study in cell culture medium demonstrated that gallium was released from the nanoparticles in a sustained manner. In direct contact with concentrations of up to 100 µg/mL of the nanoparticles, gallium-containing nanoparticles did not exhibit cytotoxicity towards pre-osteoblast MC3T3-E1 cells. Moreover, in vitro cell culture tests revealed that the addition of gallium to the nanoparticles enhanced osteogenic activity. Simultaneously, the nanoparticles disrupted the osteoclast differentiation of RAW 264.7 macrophage cells. These findings suggest that gallium-containing nanoparticles possess favorable physicochemical properties and biological characteristics, making them promising candidates for applications in bone tissue regeneration, particularly for unphysiological or pathological conditions such as osteoporosis.

A salivary urea sensor based on a microsieve disposable gate AlGaN/GaN high electron mobility transistor.

The abundant bio-markers in saliva provide a new option for non-invasive testing. However, due to the presence of impurities in the saliva background, most of the existing saliva testing methods rely on pre-processing, which limits the application of saliva testing as a convenient means of testing in daily life. Herein, a disposable-gate AlGaN/GaN high electron mobility transistor (HEMT) biosensor integrated with a micro-sieve was introduced to solve the problem of signal interference caused by charged impurities in saliva for HEMT based biosensors, where the micro-sieve was utilized as a pre-treatment unit to remove large particles of impurities from saliva through the size effect and thus greatly improving the accuracy of detection. The experimental results showed that the HEMT based biosensor has excellent linearity (R2 = 0.9977) and a high sensitivity of 6.552 µA dec-1 for urea sensing from 1 fM to 100 mM in 0.1× PBS solution. When it comes to artificial saliva detection, compared to the HEMT sensor without the micro-sieve (sensitivity = 3.07432 µA dec-1), the sensitivity of the HEMT sensor integrated with the micro-sieve showed almost no change. Moreover, to verify that urea can be detected in actual saliva, urea is sensed directly in human saliva. The addition of the microsieve module provides a new way for biosensors to detect specific markers in saliva in real time, and the designed HEMT biosensor with the microsieve function has a wide range of application potential in rapid saliva detection.

In vitroassessment of a gallium-doped glass polyalkenoate cement: chemotherapeutic potential, cytotoxicity and osteogenic effects.

Metastatic bone lesions are often osteolytic, which causes advanced-stage cancer sufferers to experience severe pain and an increased risk of developing a pathological fracture. Gallium (Ga) ion possesses antineoplastic and anti-bone resorption properties, suggesting the potential for its local administration to impede the growth of metastatic bone lesions. This study investigated the chemotherapeutic potential, cytotoxicity, and osteogenic effects of a Ga-doped glass polyalkenoate cement (GPC) (C-TA2) compared to its non-gallium (C-TA0) counterpart. Ion release profiles revealed a biphasic pattern characterized by an initial burst followed by a gradually declining release of ions. C-TA2 continued to release Ga steadily throughout the experimentation period (7 d) and exhibited prolonged zinc (Zn) release compared to C-TA0. Interestingly, the Zn release from both GPCs appeared to cause a chemotherapeutic effect against H1092 lung cancer cellsin vitro, with the prolonged Zn release from C-TA2 extending this effect. Unfortunately, both GPCs enhanced the viability of HCC2218 breast cancer cells, suggesting that the chemotherapeutic effects of Zn could be tied to cellular differences in preferred Zn concentrations. The utilization of SAOS-2 and MC3T3 cell lines as bone cell models yielded conflicting results, with the substantial decline in MC3T3 viability closely associated with silicon (Si) release, indicating cellular variations in Si toxicity. Despite this ambiguity, both GPCs exhibited harmful effects on the osteogenesis of primary rat osteoblasts, raising concerns about excessive burst Zn release. While Ga/Zn-doped GPCs hold promise for treating metastatic bone lesions caused by lung cancers, further optimization is required to mitigate cytotoxicity on healthy bone.

Electrolyte-gated amorphous IGZO transistors with extended gates for prostate-specific antigen detection.

The prostate-specific antigen (PSA) test is considered an important way for preoperative diagnosis and accurate screening of prostate cancer. Current antigen detection methods, including radioimmunoassay, enzyme-linked immunosorbent assay and microfluidic electrochemical detection, feature expensive equipment, long testing time and poor stability. Here, we propose a portable biosensor composed of electrolyte-gated amorphous indium gallium zinc oxide (a-IGZO) transistors with an extended gate, which can achieve real-time, instant PSA detection at a low operating voltage (<2 V) owing to the liquid-free ionic conductive elastomer (ICE) serving as the gate dielectric. The electric double layer (EDL) capacitance in ICE enhances the accumulation of carriers in the IGZO channel, leading to strong gate modulation, which enables the IGZO transistor to have a small subthreshold swing (<0.5 V dec-1) and a high on-state current (∼4 × 10-4 A). The separate, biodegradable, and pluggable sensing pad, serving as an extended gate connected to the IGZO transistor, prevents contamination and depletion arising from direct contact with biomolecular buffers, enabling the IGZO transistor to maintain superior electronic performance for at least six months. The threshold voltage and channel current of the transistor exhibit excellent linear response to PSA molecule concentrations across five orders of magnitude ranging from 1 fg mL-1 to 10 pg mL-1, with a detection limit of 400 ag mL-1 and a detection time of ∼5.1 s. The fabricated biosensors offer a point-of-care system for antigen detection, attesting the feasibility of the electrolyte-gated transistors in clinical screening, healthcare diagnostics and biological management.

Plasmon resonances of GZO core-Ag shell nanospheres, nanorods, and nanodisks for biosensing and biomedical applications in near-infrared biological windows I and II.

There is currently a great deal of interest in realizing localized surface plasmon resonances (LSPRs) in two distinct windows in the near-infrared (NIR) spectrum for in vivo biosensing and medical applications, the biological window (BW) I and II (BW I, 700-900 nm; BW II, 1000-1700 nm). This study aims to demonstrate that LSPRs of Ga-doped ZnO (GZO) core-silver (Ag) shell structures exhibit promising features for biological applications in the NIR BW I and II. Here, we study three different shapes for nanoshells: the core-shell nanosphere, nanorod, and nanodisk. In the calculation of the optical response of these nanoshells, an effective medium approach is first used to reduce the dielectric function of a nanoshell to that of an equivalent homogenous NP with an effective dielectric function. Then, the LSPR spectra of nanoshells are calculated using the modified long-wavelength approximation (MLWA), which corrects the polarizability of the equivalent NP as obtained by Gans theory. Through numerical investigations, we examine the impacts of the core and shell sizes of the proposed nanoshells as well as the medium refractive index on the position and line width of the plasmon resonance peaks. It is shown that the plasmon resonances of the three proposed nanoshells exhibit astonishing resonance tunability in the NIR region by varying their geometrical parameters. Specifically, the improved spectrum characteristics and tunability of its plasmon resonances make the GZO-Ag nanosphere a more viable platform for NIR applications than the spherical metal colloid. Furthermore, we demonstrate that the sensitivity and figure of merit (FOM) of the plasmon resonances may be significantly increased by using GZO-Ag nanorods and nanodisks in place of GZO-Ag nanospheres. It is found that the optical properties of the transverse plasmon resonance of the GZO-Ag nanodisk are superior to all plasmon resonances produced by the GZO-Ag nanorods and GZO-Ag nanospheres in terms of sensitivity and FOM. The FOM of the transverse plasmon mode of the GZO-Ag nanodisk is almost two orders of magnitude higher than that of the longitudinal and transverse plasmon modes of the GZO-Ag nanorod in BW I and BW II. And it is 1.5 and 2 times higher than the plasmon resonance FOM of GZO-Ag nanospheres in BW I and BW II, respectively.

Potentiality of phosphide-based nanotubes for breast cancer detection: A DFT investigation.

Breast cancer is one of the most basilisk cancers for women due to its high mortality rate which can be prevented drastically with early-stage detection. In this work, the adsorption mechanism of two volatile organic compounds that are present in the breath of breast cancer patients, 2-Methyloctane and 3, 3-Dimethylpentane, has been investigated on aluminum phosphide nanotubes (AlPNT) and gallium phosphide nanotubes (GaPNT) in order to understand their feasibility as sensor materials to diagnosis breast cancer at early stage. We have used the quantum mechanical approach by employing density functional theory using B3LYP-D3 hybrid potential for noncovalent interaction along with the LanL2DZ basis in the Gaussian 09 software package. The adsorption properties analyses suggest that GaPNT exhibits better sensing behavior as well as proclaims 12.6% greater adsorption energy for 2-Methyloctane and 9.4% greater adsorption energy for 3, 3-Dimethylpentane than AlPNT. Other structural and electric properties analyses satisfy this conclusion and suggest that GaPNT exhibits higher stability than AlPNT and could possibly be a potential candidate for developing biosensors to detect breast cancer at the preliminary stages.

An integrated electronic tag-based vertical flow assay (e-VFA) with micro-sieve and AlGaN/GaN HEMT sensors for multi-target detection in actual saliva.

Vertical flow assay (VFA) is an effective point-of-care (POC) diagnostic tool for widespread application. Nevertheless, the lack of multi-target detection and multi-signal readout capability still remains a challenge. Herein, a brand new VFA scheme for multi-target saliva detection based on electronic tags was proposed, where AlGaN/GaN HEMT sensors modified with different bio-receptors as electronic tags endowed the VFA with multi-target detection capability. In addition, the use of electronic tags instead of optical tags allowed the VFA to simultaneously carry out direct multi-target readouts, which ensure effective POC diagnostics for saliva analysis. Moreover, by integrating a hydrophilically optimized micro-sieve, impurities like sticky filaments, epidermal cells and other large-scale charged particles in saliva were effectively screened, which enabled the direct detection of saliva using AlGaN/GaN HEMT sensors. Glucose, urea, and cortisol were selected to verify the feasibility of the multi-target e-VFA scheme, and the results showed that the limit of detection (LOD) was as low as 100 aM. The linear response was demonstrated in the dynamic range of 100 aM to 100 µM, and the specificity, long-term stability and validity of the actual saliva test were also verified. These results demonstrated that the as-proposed e-VFA has potential for application in saliva detection for simultaneous multi-target detection, and it is expected to achieve the real-time detection of more biological targets in saliva.