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Detailed contact angle measurements are performed for protein drops on phenylcarbamide (PC), polymethyl methacrylate (PMMA), silicon nitride, and glass substrates by goniometer-sessile drop technique. Drop sizes are ranged from 0.1 to 6 w l with radius of curvature less than 1 mm. The bovine serum albumin (BSA) protein concentrations are 0.0, 0.1, 1.0, and 10 mg/ml. The results show weak dependence of the drop size for deionized water drops on all substrates and increased dependence of the drop size for protein drops with different protein concentrations. The significance of drop size effect varies from substrate to substrate; the effect is strongest for PC substrate, which is a nearly hydrophobic surface. The drop size dependence can be partly explained by the modified Young's equation.

The nanoscale photothermal effect and the optofluidic convection around plasmonic nanoparticles drive the application of such nanoparticles in micro-environment. In this work, heat transfer and fluid flow around Au nanospheres and nanorods in water medium under continuous and pulsed wave laser irradiance was investigated using an FEM based numerical framework. Au nanospheres of a wide range of diameter: 40 nm = Diameter (D) = 180 nm and relatively large nanorods (diameter: 50 nm) with varying aspect ratio (1 = Aspect ratio (A) = 5) and orientation (0 degrees = ? = 90 degrees, ? = 0 degrees, 90 degrees) with respect to the incident EM radiation were investigated for continuous wave (CW) and pulsed wave laser. It was found that although nanorods can attain much higher temperature than nanospheres, orientation of a nanorod is an important factor to be carefully considered in applications. In micro-scale spherical and hemispherical confinements (diameter < 14.4 p.m), the convective velocity fields around nanoparticles is in the order of 10-9 m/s, with only a weak effect of the slip or no-slip boundary condition on the confining walls. Importantly, the size of the confinement has a strong effect leading to an order of magnitude stronger convection for 14.4 p.m (diameter) spherical confinement as compared to 3.6 p.m confinement. Additionally close proximity of the nanoparticles to the confining walls strongly reduces (by an order of magnitude) the convective currents. The results reported herein provides important insights for the use of photothermal nanoparticles in microscale confined space (e.g. cellular environment) for applications such as optical tweezers, photoporation, etc.

Three-dimensional (3D) spheroid culture provides opportunities to model tumor growth closer to its natural context. The collagen network in the extracellular matrix supports autonomic tumor cell proliferation, but its presence and role in tumor spheroids remain unclear. In this research, we developed an in vitro 3D co-culture model in a microwell 3D (μ-well 3D) cell-culture array platform to mimic the tumor microenvironment (TME). The modular setup is used to characterize the paracrine signaling molecules and the role of the intraspheroidal collagen network in cancer drug resistance. The μ-well 3D platform is made up of poly(dimethylsiloxane) that contains 630 round wells for individual spheroid growth. Inside each well, the growth surface measured 500 μm in diameter and was functionalized with the amphiphilic copolymer. HCT-8 colon cancer cells and/or NIH3T3 fibroblasts were seeded in each well and incubated for up to 9 days for TME studies. It was observed that NIH3T3 cells promoted the kinetics of tumor organoid formation. The two types of cells self-organized into core-shell chimeric tumor spheroids (CTSs) with fibroblasts confined to the shell and cancer cells localized to the core. Confocal microscopy analysis indicated that a type-I collagen network developed inside the CTS along with increased TGF-β1 and α-SMA proteins. The results were correlated with a significantly increased stiffness in 3D co-cultured CTS up to 52 kPa as compared to two-dimensional (2D) co-culture. CTS was more resistant to 5-FU (IC50 = 14.0 ± 3.9 μM) and Regorafenib (IC50 = 49.8 ± 9.9 μM) compared to cells grown under the 2D condition 5-FU (IC50 = 12.2 ± 3.7 μM) and Regorafenib (IC50 = 5.9 ± 1.9 μM). Targeted collagen homeostasis with Sclerotiorin led to damaged collagen structure and disrupted the type-I collagen network within CTS. Such a treatment significantly sensitized collagen-supported CTS to 5-FU (IC50 = 4.4 ± 1.3 μM) and to Regorafenib (IC50 = 0.5 ± 0.2 μM). In summary, the efficient formation of colon cancer CTSs in a μ-well 3D culture platform allows exploration of the desmoplastic TME. The novel role of intratumor collagen quality as a drug sensitization target warrants further investigation.

Background: Due to the noninvasive nature of boron neutron capture therapy (BNCT), it is considered a promising cancer treatment method. Aim: To investigate whether polyvinyl alcohol/boric acid crosslinked nanoparticles (PVA/BA NPs) are an efficient delivery system for BNCT. Materials & methods: PVA/BA NPs were synthesized and cocultured with brain and oral cancers cells for BNCT. Results: PVA/BA NPs had a boron-loading capacity of 7.83 ± 1.75 w/w%. They accumulated in brain and oral cancers cells at least threefold more than in fibroblasts and macrophages. The IC50 values of the brain and oral cancers cells were at least ninefold and sixfold lower than those of fibroblasts and macrophages, respectively. Conclusion: Theoretically, PVA/BA NPs target brain and oral cancers cells and could offer improved therapeutic outcomes of BNCT.

International audience; Copper/bismuth sulfide heterojunctions boost the catalytic and photoresponsive properties engendered antibacterial activity against clinically isolated multidrug-resistant bacteria and their associated biofilms.We report a one-pot facile synthesis of highly photoresponsive bovine serum albumin (BSA) templated bismuth-copper sulfide nanocomposites (BSA-BiZ/CuxS NCs, where BiZ represents in situ formed Bi2S3 and bismuth oxysulfides (BOS)). As-formed surface vacancies and BiZ/CuxS heterojunctions impart superior catalytic, photodynamic and photothermal properties. Upon near-infrared (NIR) irradiation, the BSA-BiZ/CuxS NCs exhibit broad-spectrum antibacterial activity, not only against standard multidrug-resistant (MDR) bacterial strains but also against clinically isolated MDR bacteria and their associated biofilms. The minimum inhibitory concentration of BSA-BiZ/CuxS NCs is 14-fold lower than that of BSA-CuxS NCs because their multiple heterojunctions and vacancies facilitated an amplified phototherapeutic response. As-prepared BSA-BiZ/CuxS NCs exhibited substantial biofilm inhibition (90%) and eradication (>75%) efficiency under NIR irradiation. Furthermore, MRSA-infected diabetic mice were immensely treated with BSA-BiZ/CuxS NCs coupled with NIR irradiation by destroying the mature biofilm on the wound site, which accelerated the wound healing process via collagen synthesis and epithelialization. We demonstrate that BSA-BiZ/CuxS NCs with superior antimicrobial activity and high biocompatibility hold great potential as an effective photosensitive agent for the treatment of biofilm-associated infections.

We report infrared (IR) pulse laser-activated highly efficient parallel intracellular delivery by using an array of titanium microdish (TMD) device. Upon IR laser pulse irradiation, a two-dimensional array of TMD device generated photothermal cavitation bubbles to disrupt the cell membrane surface and create transient membrane pores to deliver biomolecules into cells by a simple diffusion process. We successfully delivered the dyes and different sizes of dextran in different cell types with variations of laser pulses. Our platform has the ability to transfect more than a million cells in a parallel fashion within a minute. The best results were achieved for SiHa cells with a delivery efficiency of 96% and a cell viability of around 98% for propidium iodide dye using 600 pulses, whereas a delivery efficiency of 98% and a cell viability of 100% were obtained for dextran 3000 MW delivery using 700 pulses. For dextran 10,000 MW, the delivery efficiency was 92% and the cell viability was 98%, respectively. The device is compact, easy-to-use, and potentially applicable for cellular therapy and diagnostic purposes.

In this work, we aim to study zinc oxide (ZnO)-based functional materials over cotton fabrics and their effects after gamma ray exposure of 9 kGy. We found that the binding of the nanoparticles with cotton fabrics can be enhanced after irradiation. This could be due to the oxygen deficiency or defects created in the interface between ZnO and cotton fabrics after irradiation. Near-edge X-ray absorption fine structure and X-ray photoelectron spectroscopy (XPS) were used to detect the oxygen inadequacies generated in the interior and at the surface of the ZnO nanoparticles after gamma ray exposure. XPS results showed that the binding energy of Zn shifts by 2 eV at 1.5 kGy and by 4 eV at 9 kGy. This huge shift of about 4 eV is completely different from other works due to the reaction that takes place on the interface between ZnO nanostructures and cotton fabrics after gamma ray irradiation. Overall, this work suggests that after gamma ray irradiation, there is an enhanced level of binding between the coated functional nanoparticles and cotton fabrics, which can be advantageous for the textile industries.

In this paper, a phosphoric acid fuel cell integrated with reformer and evaporator is demonstrated. Oxidative steam reforming of methanol (OSRM) process is employed in this system in cooperated with a high efficient evaporator, and the reacted gas is sent into a phosphorus-acid fuel cell (PAFC) for direct power generation after surplus methanol/water filtration. The results show that the maximum power density of this hybrid system achieves 277 mW/cm2 without CO2 removal, while it achieves 485 mW/cm2 when employing pure hydrogen as the fuel.

Proteins are the essential components of all living creatures that link genes and bio-functionalities, and their crystallizations have attracted much interest as the study of the 3D structures thro...

Aim: To improve the killing efficacy of head and neck squamous cells (SAS) by boric acid-mediated boron neutron capture therapy (BNCT). Materials & methods: Boric acid-containing chitosan/alginate/polyvinyl alcohol nanoparticles (B-capNPs) were manufactured using the nano-electrospray process. Results: Less than 10% of the boric acid leaked from the B-capNPs over 2 days. The B-capNPs killed up to 2.8-fold more SAS cells and reduced cytotoxicity tenfold when compared with pure boric acid alone. B-capNPs show selective uptake in tumor cells with tumor/normal ratios of SAS to normal (NIH 3T3) and macrophage (RAW 264.7) cells of 4.0 and 3.5, respectively, which are greater than the minimum acceptable tumor/normal ratio for BNCT of 2.5. Conclusion: These findings illustrate that B-capNPs may be more superior as BNCT drugs than pure boric acid.

Electrodynamic systems for bioanalytical applications constantly suffer from biofouling due to electrical field-induced nonspecific bioadsorption on electrode surfaces. To minimize this issue, surface modification using anti-biofouling and conductive materials is necessary to not only protect the electrode surface from nonspecific bioadsorption but also maintain desired electrodynamic properties for electrode operation. In this study, we designed and prepared a conductive, zwitterionic, and self-doped sulfonated polyaniline (SPANI) coating on Au electrode surfaces for anti-biofouling applications. The zwitterionic coating was fabricated by electrochemical polymerization of aniline on the Au electrode surface functionalized with cysteamine (HS-CH2CH2-NH2) and then a post-polymerization treatment with fuming sulfuric acid. We found that the SPANI-coated electrodes exhibited an excellent anti-biofouling ability in dielectrophoresis (DEP) capturing-and-releasing processes, with a very low average residual mass rate of 1.44% for the SPANI-5s electrode, whereas electrodes modified with poly(ethylene glycol) (PEG) gave an average residual mass rate of 14.30%. Even under continuous operation for more than 1 h, the SPANI-5s electrode still showed stable anti-biofouling ability for an 11-cycle E. coli capturing-and-releasing DEP process, with the residual mass rate for all 11 cycles being kept at or below 2.18% to give an average residual mass rate of 1.62% with a standard deviation of 0.40%. This study demonstrates that electrodynamic systems with zwitterionic SPANI coated on open electrode surfaces can excellently function with decent conductance and anti-biofouling performance.

The ability to deliver foreign cargos into single living cells is of great interest in cell biology and therapeutic research. Here, we have reported a single or multiple position based nano-localized single-cell nano-electroporation platform. The device consists of an array of triangular shape ITO nano-electrodes with a 70 nm gap between two nano-electrodes, each having a 40 nm tip diameter. The voltage is applied between nano-electrodes to generate an intense electric field, which electroporates multiple nano-localized regions of the targeted single-cell membrane, and biomolecules are gently delivered into cells by pressurizing pump flow, without affecting cell viability. The platform successfully delivers dyes, QDs, and plasmids into different cell types with the variation of field strength, pulse duration, and the number of pulses. This new approach allows us to analyze delivery of different biomolecules into single living cells with high transfection efficiency (>96%, for CL1-0 cells) and high cell viability (∼98%), which are potentially beneficial for cellular therapy and diagnostic purposes.

Targeted intracellular delivery of biomolecules and therapeutic cargo enables the controlled manipulation of cellular processes. Laser-based optoporation has emerged as a versatile, non-invasive technique that employs light-based transient physical disruption of the cell membrane and achieves high transfection efficiency with low cell damage. Testing of the delivery efficiency of optoporation-based techniques has been conducted on single cells in monolayers, but its applicability in three-dimensional (3D) cell clusters/spheroids has not been explored. Cancer cells grown as 3D tumor spheroids are widely used in anti-cancer drug screening and can be potentially employed for testing delivery efficiency. Towards this goal, we demonstrated the optoporation-based high-throughput intracellular delivery of a model fluorescent cargo (propidium iodide, PI) within 3D SiHa human cervical cancer spheroids. To enable this technique, nano-spiked core–shell gold-coated polystyrene nanoparticles (ns-AuNPs) with a high surface-to-volume ratio were fabricated. ns-AuNPs exhibited high electric field enhancement and highly localized heating at an excitation wavelength of 680 nm. ns-AuNPs were co-incubated with cancer cells within hanging droplets to enable the rapid aggregation and assembly of spheroids. Nanosecond pulsed-laser excitation at the optimized values of laser fluence (45 mJ cm(−2)), pulse frequency (10 Hz), laser exposure time (30 s), and ns-AuNP concentration (5 × 10(10) particles per ml) resulted in the successful delivery of PI dye into cancer cells. This technique ensured high delivery efficiency (89.6 ± 2.8%) while maintaining high cellular viability (97.4 ± 0.4%), thereby validating the applicability of this technique for intracellular delivery. The optoporation-based strategy can enable high-throughput single cell manipulation, is scalable towards larger 3D tissue constructs, and may provide translational benefits for the delivery of anti-cancer therapeutics to tumors.

This study demonstrates a novel multi-functional microfluidic system, designated three dimensional Alternative Current Electrokinetic/Surface Enhanced Raman Scattering (3D-ACEK/SERS), which can concentrate bacteria from whole blood, identify bacterial species, and determine antibiotic susceptibilities of the bacteria rapidly. The system consists of a hybrid electrokinetic mechanism, integrating AC-electroosmosis (AC-EO) and dielectrophoresis (DEP) that allows thousand-fold concentration of bacteria, including S. aureus, Escherichia coli, and Chryseobacterium indologenes, in the center of an electrode with a wide range of working distance (hundreds to thousands of μm), while exclusion of blood cells through negative DEP forces. This microchip employs SERS assay to determine the identity of the concentrated bacteria in approximately 2 min with a limit of detection of 3 CFU/ml, 5 orders of magnitude lower than that using standard centrifugation−purification process. Finally, label-free antibiotic susceptibility testing has been successfully demonstrated on the platform using both antibiotic-sensitive and multidrug-resistant bacterial strains illustrating a potential utility of the system to clinical applications.

A novel composite membrane consisting glass microfiber (GMF) and polytetrafluoroethylene (PTFE) nanoporous film is applied to phosphoric acid fuel cell (PAFC) for performance enhancement and reducing electrolyte leakage. With 93% high porosity, the GMF can fully load phosphoric acid to maintain high proton conductivity. However, the large opening of the GMF membrane cannot effectively prevent the leakage of phosphoric acid. Therefore, in this study, a 25 μm thick PTFE thin film with pore size 50–400 nm is employed to cover the surface of GMF for preventing phosphoric acid leakage. This composite proton exchange membrane possesses both thermal and chemical stability at the working temperature of phosphoric acid fuel cell, while providing high proton conductivity. The proton conductivity of the composite membrane (0.71 S/cm at 150 °C) is much higher than those of reported phosphoric acid porous membranes (∼10−2 S/cm at 150 °C). The fuel cell using the composite membrane with Pt/C catalyst exhibits excellent performance with peak power density of 614 mW/cm2 and current density of 1761 mA/cm2 at 140 °C under pure H2 and O2 supply, while proton conductivity is maintained 2.6 times higher than that of the pure GMF membrane due to the less phosphoric acid leakage by using PTFE film.

Bovine serum albumin (BSA)-encapsulated copper sulfide nanocrystals (CuS NCs) were prepared by heating an alkaline solution containing copper ions and BSA without an additional sulfur source. At a high BSA concentration (0.8 mM), nanoassembly of the as-formed CuS NCs occurs to form BSA-CuS NCs as a result of the formation of BSA gel-like structures. In addition to their intrinsic photothermal properties, the BSA-CuS NCs possess rich surface vacancies and thus exhibit enzyme-like and photodynamic activities. Spontaneous generation of hydrogen peroxide (H2O2) led to the in situ formation of copper peroxide (CPO) nanodots on the BSA-CuS NCs to catalyze singlet oxygen radical generation. The antimicrobial response was enhanced by >60-fold upon NIR laser irradiation, which was ascribed to the combined effect of the photodynamic and photothermal inactivation of bacteria. Furthermore, BSA-CuS NCs were transdermally administered onto a methicillin-resistant Staphylococcus aureus-infected wound and eradicated >99% of bacteria in just 1 min under NIR illumination due to the additional peroxidase-like activity of BSA-CuS NCs, transforming H2O2 at the infection site into hydroxyl radicals and thus increasing the synergistic effect from photodynamic and photothermal treatment. The BSA-CuS NCs exhibited insignificant in vitro cytotoxicity and hemolysis and thus can serve as highly biocompatible bactericides in preclinical applications to effectively eradicate bacteria.

Cellular transfection is a method by which exogenous biomolecules can be introduced into the cells. In the fields of molecular and cellular biology, cellular transfection is considered an essential tool, specifically for applications such as drug delivery, cellular therapy, and biomedical imaging. Photoporation based cellular transfection approach uses high-intensity light energy to create membrane pores, sometimes nanoparticles are incorporated to achieve the result at low intensity. In this work, hybrid nanoparticles, composed of gold and polystyrene are used to mediate the photoporation. Laser fluence, exposure time, wavelength, the concentration of nanoparticles, and concentration of exogenous molecules are optimized for the successful delivery of propidium iodide dye, quantum dots, and plasmid into CL1-0, AGS, and P-19 cells. The best results (delivery efficiency of 92% and cell viability of 98%) are achieved in delivering propidium iodide dye into CL1-0 cells.

A solid substance is considered as a nanomaterial if it has at least one face in the dimension range of 1–100 nm. Nanomaterials, because of their small size and exceptionally high surface area, display electromagnetic, optical, and piezoelectric properties, and have enormous applications in various fields such as wastewater treatment, oil, and gas industry, energy storage, bio-imaging, and healthcare diagnostics and treatment. Nanomaterials provide flexibility to the sensing platforms and also even allow mobility between various detection techniques. In the last few decades, many nanomaterials have been developed for various applications, and considerable interest has been gained in the field of medical diagnosis and therapy in recent years. The innovations in nanomaterial preparation and their modifications have led to the development of devices and assays used for biomedical applications, which are faster, less expensive, accurate, and sensitive. Despite having excellent material properties, many nanomaterials are affected by the lack of surface heterogenic reactivity, which is critical for the surface immobilization of essential biomarkers. Thus the nanomaterials need to go through surface modifications to improve the adsorption capacity of biomolecules to the functionalized surface. In this chapter, various surface modifications of nanomaterials, including metallic nanoparticles, carbon nanomaterials, nanoceramics, and self-assembled materials, have been discussed for various applications in general and more attention has been given to biomedical applications in particular.

Stone coal is a kind of carbonaceous shale that contains vanadium. The sequential chemical extractions were adopted to analyze the vanadium phases of stone coal and its combustion fly ash. The results showed that the vanadium in stone coal mainly consisted in aluminosilicate. The vanadium in fly ash mainly existed in organic matter, aluminosilicate and Fe–Mn oxides, and the other vanadium existed in exchangeable fraction. Through the burning process, the vanadium was released and enriched in fly ash. Because of particular vanadium migration behaviors, the distribution of vanadium in phases became more scattered, and the leaching of vanadium in fly ash was easier than that in stone coal.

In this paper, a nanobiosensor with surface-enhanced Raman scattering (SERS) capability is introduced for highly sensitive miRNA detection in colorectal cancer. This sensor was designed and fabricated by employing a nanoshielding mechanism from nanopolystyrene beads to resist reactive ion etching and allow anisotropic electrochemical etching, producing high-aspect-ratio, surface-corrugated nanopillars (SiNPs) on a silicon wafer to create extensive hot spots along the nanopillars for improved SERS signals. SERS enhancements were correlated with nanorange roughness, indicating that hot spots along the pillars were the crucial factor to improve the SERS effect. We achieved the detection capability of a trace amount of R6G (10&minus, 8 M), and the SERS signal enhancement factor (EF) was close to 1.0 &times, 107 on surface-corrugated gold SiNPs. miRNA samples were also demonstrated on this sensor with good sensitivity and specificity. The target molecule miR-21-Cy5 was easily monitored through Raman spectrum variation with a PCR-comparable concentration at around 100 pM with clear nucleotide-specific Raman signals, which is also suitable for biomolecule sensing.

Celery spices are an important raw material in the production of food and cosmetic, including carveol, carvone and dihydrocarvone. In this study, a new Klebsiella sp. O852 was isolated, which was capable of converting limonene to trans-dihydrocarvone. The yields of trans-dihydrocarvone reached up to 1058 mg/L when the strain O852 was incubated using LB-M medium for 4 h at 36oC and 150 rpm and the process was monitored for 36 h after adding 1680 mg/L limonene dissolved in ethanol. Limonene was used as a 20% (v/v) solution in the ethanol. Besides, the genome of Klebsiella sp. O852 comprised 20 contigs and 19 scaffolds. The genome size was 5.49 Mb. A total of 5218 protein-encoding genes were predicted, these genes mainly distributed in some metabolism and biosynthesis categories. Finally, several genes involved in trans-dihydrocarvone biosynthesis were further analyzed, identified and verified by quantitative real-time polymerase chain reaction (RT-qPCR) and exogenous expression. These novel genes may find value in the bioconversion of inexpensive raw materials to natural flavors and fragrances.

Cells are known to be the most fundamental building block of life [...]

Tissue-specific microenvironmental factors contribute to the targeting preferences of metastatic cancers. However, the physical attributes of the premetastatic microenvironment are not yet fully characterized. In this research, we develop a transwell-based alginate hydrogel (TAH) model to study how permeability, stiffness, and roughness of a hanging alginate hydrogel regulate breast cancer cell homing. In this model, a layer of physically characterized alginate hydrogel is formed at the bottom of a transwell insert, which is placed into a matching culture well with an adherent monolayer of breast cancer cells. We found that breast cancer cells dissociate from the monolayer and home to the TAH for continual growth. The process is facilitated by the presence of rich serum in the upper chamber, the increased stiffness of the gel, as well as its surface roughness. This model is able to support the homing ability of MCF-7 and MDA-MB-231 cells drifting across the vertical distance in the culture medium. Cells homing to the TAH display stemness phenotype morphologically and biochemically. Taken together, these findings suggest that permeability, stiffness, and roughness are important physical factors to regulate breast cancer homing to a premetastatic microenvironment.

We have prepared copper nanoclusters (Cu NCs) in the presence of bovine serum albumin (BSA) and 1,3-propanedithiol (PDT). The PDT/BSA-Cu NCs possess great activities against different types of bacteria, including non-multidrug-resistant bacteria (Escherichia coli, Salmonella Enteritidis, Pseudomonas aeruginosa, and Staphylococcus aureus) and multidrug-resistant bacteria (methicillin-resistant S. aureus). Their minimal inhibitory concentration (MIC) values are at least 242-fold and 10-fold lower than that of the free PDT and BSA-Cu NCs, respectively. The PDT/BSA-Cu NCs are strongly bound to the bacterial membrane, in which they induce the generation of ascorbyl (Asc) and perhydroxyl (HOO) radicals that result in disruption of their membrane integrity. At a concentration of 100-fold higher than their MIC for Escherichia coli, the PDT/BSA-Cu NCs exhibit negligible cytotoxicity towards the tested mammalian cells and show insignificant hemolysis. We have further demonstrated that low-cost PDT/BSA-Cu NCs-coated carbon fiber fabrics (CFFs) are effective against antibacterial growth, showing their great potential for antifouling applications.

To provide sufficient hydrogen at lower temperature ( −4 mol/min, or 644.8 ml/min/cm3, at 180 °C) is developed and integrated with a high performance PAFC. Compared to the previous reformer [26], the performance of the current reformer can produce 39.4 folds more hydrogen throughput at a much lower temperature (180 °C, decreased from 225 °C) with compatible methanol conversion rate (83%), owing to the synergic effects from optimizing the catalyst amount and reactive area, enlarging the depth of the channel, and increasing the concentration and flow rate of reactant fuel. Commendably, 79% methanol conversion rate and 5.2 × 10 −4 mol/min hydrogen production yield can also be obtained at much lower operation temperature of 130 °C. In integration testing, a 132 mW/cm 2 power density is generated by directly employing the reformed gas (41.6% H2, 28.1%H2O, 28.5% CO2, and 1.8% CO) as the fuel to a small PAFC, a roughly 45.8% power generation efficiency is obtained when compared to that by injecting pure Hydrogen gas into the same PAFC, demonstrating a compatible performance when considering hydrogen of only 41.6% purity is provided.

In this study, we controlled the growth of crystalline plane to synthesize the vertical platinum nanopelts onto fluorine doped tin oxide (FTO) glass to construct the platinum nanoroses (PtNRs) by an easy electrochemical deposition (ECD) method at room temperature in the normal atmospheric environment, and applied the PtNRs as a counter electrode (CE) for dye-sensitized solar cell (DSSC). The morphologies and crystalline nanostructures of the ECD PtNRs were examined by field emission scanning electron microscopy and the high-resolution transmission electron microscopy. The electrocatalytic properties of the ECD PtNRs were analyzed by cyclic voltammetry and electrochemical impedance spectrum. The power conversion efficiency (PCE) of the DSSC assembled with the ECD PtNRs CE was examined under the illumination of AM 1.5 (100 mWcm − 2 ). The ECD PtNRs showed well contact behavior with FTO surface and offered a large surface area to promote the redox reaction rates therefore increased the exchange current density. Due to the PtNRs showed the macroporous structure, the electrolyte can easily diffuse through the open space between the nanopelts, resulting in improved kinetics for charge-transfer processes and reduced the charge-transfer resistance. Our findings suggest that the catalytic efficiency of PtNRs with a specific crystal plane was significantly greater than that of a traditional Pt film catalyst. In combination with a N719 dye-sensitized TiO 2 working electrode and an iodine-based electrolyte, the DSSC assembled with the PtNRs CE achieved a PCE of 6.58%, almost 10% higher than that of a cell prepared with a conventional sputtering Pt film CE (6.00%). These results provide a potential strategy for electrochemical catalytic applications.

In this study, a pulse-mode electrochemical deposition technique was employed to deposit dense and homogeneous Ni nanoparticles on the three-dimensional graphene network (3DGN) as the catalysts for growing the vertical aligned one-dimensional carbon nanofibers (CNFs) to fabricate the full-carbon hybrid nanoarchitecture of CNFs/3DGN for the supercapacitors. When tested as electrode for a supercapacitor, the CNFs/3DGN hybrid nanoarchitecture demonstrated to possess a large surface area and showed an excellent specific capacitance of 59.28 F g −1 at a current density of 0.17 mA cm −2 , also displayed good cycle stability with capacitance retention of 93.9% after 10,000 cycles in 6 M KOH electrolyte.

Hydrogen has been recognized as a future energy carrier that may allow a gradual transformation from a fossil fuel-based economy to a hydrogen economy. One of main obstacles to implement hydrogen economy is efficient storage of hydrogen. Up to present, none of proposed storage methods completely satisfy all department of energy (DOE) target criteria with gravimetric capacity ~5.5 wt% and loss rate 0.1 (g/h)/kg for hydrogen storage yet. Here we demonstrate high density of hydrogen nano-bubble (HNB) up to ~3.4±0.18 wt% can be efficiently generated and stored via an electron radiolysis assisted abstraction reaction (RAAR) in an encapsulated quasi-2D water reservoir containing organic molecules. The RAAR is a reaction between radiolytic water species and the surface groups of organic molecules. In our system, the long term stability of HNB comes from supersaturation of hydrogen molecules controllable by the electron dose rate and concentration of the organic molecule. The best gravimetric capacity and loss rate in our experiment are ~3.4±0.18 wt% and 0.18(g/h)/kg, respectively, in 25 °C and at 1 bar which fall closely to the DOE targets. A TEM equipped with a continuous flow holder with a quasi-2D water reservoir is utilized for in-situ generation and storage of HNB. The regeneration time for HNB formation is in the order of a few ten seconds. This process can be linked with the microbial electrolysis cell technology that converts hydrogen from wastewater containing abundant organics.

Two-dimensional (2D) molybdenum disulfide (MoS2) nanosheets were synthesized to anchor onto the surfaces of directly grown one-dimensional (1D) carbon nanotubes (CNTs) on fluorinated tin oxide (FTO) glass. This three-dimensional (3D) vertically aligned hybrid nanoarchitecture was used in Pt-free counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The prepared 2D MoS2 nanosheets, with exposed layers, provided a great deal of edge-plane catalytically active sites for I3− reduction. The directly grown 1D CNTs provide an attractive template that offers a large surface area to promote the loading of 2D MoS2 nanosheets for enhancing electrochemical activity. The CNTs directly grown on the FTO substrate provided a high-speed pathway that promoted charge transport and transfer, resulting in a lower electron lifetime that increased the exchange current density and reduced the charge-transfer resistance. The DSSCs assembled with the 3D vertically aligned MoS2/CNT hybrid nanoarchitecture CE achieved a power conversion efficiency of 7.83%, 9.5% higher than that of a cell prepared with a Pt film CE (7.15%).

This study develops a silicon-based microfluidic device incorporating a micro reformer that employs the partial oxidation of methanol (POM) reaction and a microchannel heat exchanger (MCHE) for potential reforming methanol fuel cell application. Two-dimensional temperature distribution of the reformer and two-phase flow evolution in the MCHE are acquired by infrared (IR) thermography and high-speed digital camera images, respectively. The composition of gas products is further analyzed by gas chromatography. The maximal hydrogen production rate of 2.97 × 10−5 mol/s and selectivity of 77.3% are obtained in the present study. Thermal images of the reformer indicate that the POM reaction is more intense near the outlet, and the high-temperature region expands from the outlet to inlet regions with time until the steady state is reached. The present study reveals that IR thermography with proper calibration facilitates real-time temperature monitoring, which enables understanding the distribution of the reforming reaction and its evolution through the reformer until the steady state is reached. The shortest time for approaching the steady state is only 8 s for the present system under certain conditions. The data obtained may provide a basis for theoretical and numerical analyses on the progress of temperature and reforming reaction. In addition, the present results demonstrate that the micro evaporator may effectively use the heat produced from the exothermic POM reaction and provide low-temperature hydrogen for possible application in fuel cells.

In this paper we propose a nano-shield mechanism via polystyrene beads (PSBs) to resist the chemical etching, simultaneously produce a highly selective etching ratio to create more hot-spots for Surface-enhanced Raman spectroscopy (SERS) enhancement of a Janus-Biosensor. In this paper reports an improved method for processing nona-pillar array structure characterized by High-Aspect-Ratio, which extend the third dimension of hot-spots distribution. After depositing gold, nano-pillar array produce more hot-spots for greater SERS enhancement around 10 times than original substrate, which sensor could be proposed as high sensitivity bio-sensing application purpose.With this SERS substrate, we can improve the sensitivity to distinguish clearly of the hybridization process by Raman spectrum in label-free way. With this method, we will have a widespread implication in DNA analysis. Especially detecting biomarkers in liquid biopsy field, to achieve the final purpose of early cancer screening.

OBJECTIVE: To improve the existing manually-assembled cochlear implant electrode arrays, a thin film electrode array (TFEA) was micro-fabricated to have a maximum electrode density of 15 sites along an 8-mm length, with each site having a 75 × 1.8-μm (diameter × height) disk electrode. METHODS: The micro-fabrication method adopted a sequence of photoresist transferring, lift-off, two-step oxygen plasma etching, and fuming nitric acid release to reduce lift-off complexity, protect the metal layer, and increase the release efficiency. RESULTS: Systematic in vitro characterization showed that the TFEA’s bending stiffness was 6.40 × 10(−10) N·m(2) near the base and 1.26 × 10(−10) N·m(2) near the apex. On average, the TFEA electrode produced an impedance of 16 kΩ and a maximum current limit of 800 μA, measured with a 1-kHz sinusoidal current using monopolar stimulation in saline. A TFEA prototype was implanted in a cat cochlea to obtain in vivo measurements of electrically-evoked auditory brainstem and inferior colliculus responses to monopolar stimulation with 41-μs/phase, biphasic pulses. Both physiological responses produced a threshold of ~300 μA and a dynamic range of 5–8 dB above the threshold. Comparing with existing electrode arrays, the present TFEA had 10(4) times less bending stiffness, 97% less electrode area, and comparable physiological thresholds. CONCLUSION: Using a simplified structure and stable fabrication method, the present TEFA produced physical and physiological performance comparable to existing commercial devices. SIGNIFICANCE: The present TFEA and micro-fabrication method represent a step closer towards an automated process replacing the labor-intensive and expensive manual assembly of electrode arrays in most neural prostheses including the cochlear implant.

Early diagnosis of bacterial infections is crucial to improving survival rates by enabling treatment with appropriate antibiotics within the first few hours of infection. This paper presents a highly sensitive amperometric biosensor for the detection of several pathogenic bacterial cells in blood plasma around 30 min. The proposed device is based on an electropolymerized self-assembled layer on gold nanoparticles operated in a portable nano-sieving microfluidic system (NS-MFS). The redox-active gold nanoparticles (raGNPs) enhanced the electrical conductivity and provided a greater number of electrochemically active molecules for sensing, while improving resistance to the fouling of sensors by oxidation products in blood plasma. The detection limit of the device has been shown to reach 10 CFU/mL for Pseudomonas aeruginosa and Staphylococcus aureus spiked in plasma. The dynamic range of the sensing system falls between 10 and 105 CFU/mL in a buffer solution by cyclic voltammetry (CV) measurements. The results demonstrated that the raGNPs/NS-MFS can successful detect P. aeruginosa and S. aureus in human plasma, and is very useful for the diagnosis of bacteremia from clinical samples.

Colorectal cancer (CRC) is the second most common cause of cancer-related death worldwide. Detecting and enumerating circulating tumor cells (CTCs) in patients with colorectal cancer emerged as an important prognostic tool which provides a direct estimate of metastatic potential. Improving the turnaround time and decreasing sample volume is critical for incorporating this liquid biopsy tool into routine practice. The objective of the current study was to validate the clinical feasibility of a self-assembled cell array (SACA) chip, a CTC counting platform with less than 4 h turnaround time, in patients with newly diagnosed colorectal cancers. In total, 179 patients with newly diagnosed colorectal cancers from a single institute were enrolled. Epithelial cell adhesion molecule positive (EpCAM(+)), cluster of differentiation 45 negative (CD45(−)) cells were isolated and enumerated from 2 mL of peripheral vein blood (PB) and inferior mesenteric vein blood (IMV) samples obtained during surgery. We found that the CTC count in PB but not IMV correlates with disease stages. Neoadjuvant chemotherapy did not lead to decreased CTC count in both types of blood samples. With cutoffs of four CTCs per 2 mL of blood, and serum carcinoembryonic antigen (CEA) level of 5 ng/mL, patients with non-metastatic disease were more likely to experience recurrence if they had high PB CTC count and high serum CEA concentration (odds ratio, 8.9). Our study demonstrates the feasibility of enumerating CTCs with a SACA chip in patients with colorectal cancer.

Ni–Mo ore is a multi-metal complex and unique mineral resource that exists as a black shale. This ore contains more than 4 wt% Mo and at least 2 wt% Ni. Economic value is associated with deriving products from Ni–Mo ore that contains amorphous colloidal sulfides and that is highly active. Under low-temperature hydrothermal conditions (water at 120 °C or more) and in excess oxygen, amorphous sulfides are oxidized easily to metal-sulfate forms, which leads to nickel and molybdenum dissolution. In this study, the effects of agitation speed, temperature, oxygen partial pressure and particle size on the rate of nickel leaching were investigated. The leaching rate was nearly independent of agitation speed above 400 rpm and increased with a decrease in particle size. A temperature increase to 150 °C contributed significantly to the nickel leaching rate. Oxygen pressure influences nickel leaching, with an oxygen pressure of between 0.5 MPa and 0.7 MPa providing the greatest effect. The pressure-leaching behavior of nickel was fitted to a shrinking-core kinetic model. The mathematical analyses indicates that the dissolution process is chemical-reaction controlled during early dissolution, with an activation energy of 42.68 kJ/mol, and the reaction order with respect to the oxygen partial pressure was 0.79. Up to nearly 70 % nickel was dissolved into solution, and product layers of molybdenum and iron oxide were formed on the surface of the Ni–Mo ore particles, which prevented further nickel dissolution. Thereafter, nickel leaching was controlled by liquid-film diffusion, with an activation energy of 11.01 kJ/mol.

In this work, we synthesized metal (Au, Ag or Cu)–based nanoclusters (NCs) with different photoluminescence (PL) properties and investigated their application for the specific detection of heavy metal ions in water samples. Bovine serum albumin (BSA) and thiosalicylic acid (TSA) acted as protecting ligands for the synthesis of metallic NCs (MNCs). The as–prepared TSA/BSA–Au NCs, TSA/BSA–Ag NCs and TSA/BSA–Cu NCs exhibit PL emission at 700, 624, and 430 nm, with average lifetimes of 1540, 30.9, and 11.7 ns, respectively, when excited at 350 nm. MNCs has a metal core and metal–thiolate shell, where shell species are Au38–SR24, Ag9–SR7 and Cu3–14–SRm in the TSA/BSA–Au NCs, TSA/BSA–Ag NCs, and TSA/BSA–Cu NCs, respectively. PL quenching of MNCs induced through metallophilic interaction, metal–thiol complexation and/or inner filter effect, which enables the quantitation of Hg2+, As3+, and Cr6+ ions, with linear ranges of 1–350, 1–20, and 50–400 nM, and with limits of detection of 0.25, 0.34 and 3.54 nM, respectively. The TSA/BSA–Au NCs, TSA/BSA–Ag NCs, and TSA/BSA–Cu NCs probe systems exhibit the advantages of simplicity, rapidity, selectivity, sensitivity, and practicality for the quantitation of metal ions in water samples.

Fabrication of three-dimensional (3D) SU-8 (an epoxy-based negative photoresist from MicroChem) prisms as low-loss couplers for interconnection between optical components, particularly optical fibers and silicon-on-isolator waveguides (SOI WGs), which have mismatched mode sizes, has been investigated. With an interfacial structure formed by a 3D SU-8 prism partly overlaying an SOI WG end with a portion of buried oxide (BOX) removed under the interface, low-loss coupling is ensured and the transmission efficiency can reach 70%. To fabricate these 3D SU-8 prisms, a simple method with two photolithography steps was used for SU-8 hinges and CYTOP (an amorphous fluoropolymer from AGC Chemicals) prism windows, with mild soft and hard bakes, to define the prism profiles with diluted SU-8 filled in the CYTOP prism windows. A buffered oxide etchant is used to remove BOX parts under the interfaces. Some of the fabricated structures were tested, demonstrating the contribution of overlaying SU-8 prisms to the transmission efficiency of optical interconnections between fibers and SOI WGs.

Direct methanol fuel cells (DMFCs) are expected to play a central role in portable power source applications. However, the low efficiency of the methanol oxidation reaction (MOR) has limited their commercial use. To solve this issue, three-dimensional gold dendritic nanoforests (Au DNFs) were prepared to achieve photo-enhanced MOR at the DMFC anode. These approximately 1-μm-thick silicon-supported free-standing nanostructures were fabricated in 5 min under ambient conditions by a facile fluoride-assisted galvanic replacement reaction. Their catalytic performance and photo-enhancement toward MOR were investigated via cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy. Clear catalytic activity enhancement and charge transfer resistance reduction were discovered under illumination. In addition, the chronoamperometric test showed that the oxidation current of MOR was boosted by 28% under broadband illumination. The optimal photoresponse was obtained at 700 nm. These results demonstrate the strong applicability of Au DNFs to photo-electrochemical cells. Furthermore, the fabrication method provides a rapid bottom-up synthetic strategy for silicon-supported free-standing metallic nanostructures.

The effective and efficient treatment of diseases, such as HIV, cancer or hereditary diseases, requires accurate and precise control of the combinatorial drug-dosage and their release. Herein, we introduce a simple photosensitive poly(ethylene glycol) diacrylate (PEGDA) hydrogel based platform for high dynamic range testing of combinatorial cocktail drug screening using three chemical and two protein drug treatments for colon cancer. UV cross linked PEGDA hydrogel droplet arrays on a Teflon patterned glass substrate enable a rapid yet accurate selection and dosage assignment of the drugs. Precisely loaded cocktails of the anticancer drugs were simultaneously released in-parallel with the PEGDA hydrogel chips into 2D or 3D cultured HCT-8 colon cancer cells for combinatorial drug screening. We demonstrate the functionality of our UV gel-Drug Chips 1000 fold range of concentrations for each of the five drugs in 30 seconds to find the optimized drug cocktail using a fractional factorial control system. Our device has low drug consumption, requiring only 12 nL per screening run per droplet. In addition, our UV gel-Drug Chips were employed for find the optimized drug cocktail using a fractional search algorithm. Our cocktail drug response results for both 2D (cell viability is 7.3%) and 3D (cell viability is 10.8%) colon cancer cells were analogous to those found by conventional method (6.8 and 9.3 respectively). In contrast to conventional method, our approach is faster, more effective, less time consuming and requires a lower amounts of drug volume.

Single-cell electroporation is a powerful technique to understand cellular behavior with heterogeneity, which might be impossible based on bulk measurements of millions of cells together. In this study, a dielectric passivation layer was deposited on top of an indium-tin oxide micro-electrode-based transparent chip surface using a plasma enhanced chemical vapour deposition technique. We theoretically and experimentally investigated the key effects of the dielectric passivation layer on localized single-cell electroporation for different cancer cells, which were randomly distributed with a high density throughout the chip surface as a monolayer. The passivation layer not only prevented the conventional or bulk electroporation with bubble and ion generation, but also provide an intense electric field in-between electrode gap for localized single-cell electroporation with high cell viability. Thus, devices with dielectric passivation layers are potentially applicable for single-cell studies.