Safety evaluation of rare ginsenosides of stems and leaves from American ginseng: 90-day exposure toxicity study combined with intestinal flora analysis and metabonomics in rats.

Rare ginsenosides have already been widely applied in many fields, including health food and bio-medicine. The human being can expose to rare ginsenosides directly or indirectly increasingly. However, there are few studies on the safety assessment of rare ginsenoside mixtures. In the present study, the sub-chronic toxicity of rare ginsenosides for 90 days on SD rats was performed by combining the intestinal flora analysis and urine metabonomics aiming to illustrate the safety of long-term consumption of rare ginsenosides and the potential damage for liver and intestinal. 48 adult rats were divided into four groups: control (0 mg/kg), low-dose (60 mg/kg), medium-dose (200 mg/kg), and high-dose (600 mg/kg). Rats in the high-dose group showed inflammatory changes in their livers and intestines. The strong bactericidal effect of rare ginsenosides caused intestinal flora disorder and changed the structure of intestinal flora in rats, thus inducing intestinal damage in rats. In the high-dose group, levels of alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and alkaline phosphatase (AKP) increased significantly. As a result of the high-dose treatment, certain metabolic pathways were altered, such as vitamin B6 metabolism, methionine metabolism, glutathione metabolism, and others. These results indicated that high doses of rare ginsenosides induced liver injury by affecting the above metabolic pathways. Rare ginsenosides with no observed adverse effect level (NOAEL) were below 200 mg/kg/day in vivo. Thus, this present study provides insight into the rational use of rare ginsenosides.

Oxidative damage induced by combined exposure of titanium dioxide nanoparticles and cypermethrin in rats for 90 days.

Titanium dioxide nanoparticles (TiO2NPs) and cypermethrin (CPM) are widely used in various fields, and they can enter the environment in different ways. Combined exposure of TiO2NPs and CPM may increase the accumulation of pollutants in organisms and affect human health. This study was undertaken to evaluate the oxidative and inflammatory parameters associated with the combined exposure of TiO2NPs and CPM in rats. Twenty-four healthy male adult SD rats were randomly divided into four groups. The first group served as the control, while groups 2, 3, and 4 were treated with TiO2NPs (450 mg/m3); CPM (6.67 mg/m3) or combined exposure of TiO2NPs and CPM by inhalation for 90 days. We investigated the oxidative damage induced through combined exposure of TiO2NPs and CPM in rats by evaluating hematology of the rats and determining the blood biochemical index. Our results demonstrated that inhalation of TiO2NPs and CPM increased the levels of oxidative stress markers such as malondialdehyde and alkaline phosphatase in the serum of rats. These were accompanied by a decreased glutathione peroxidase and total superoxide dismutase levels. Furthermore, the level of glutathione peroxidase was further decreased while malondialdehyde was increased in the combined exposure of TiO2NPs and CPM. Interestingly, pathological sections showed that different degrees of tissue injury could be seen in the liver and lung tissues of each exposure group. In summary, the combined exposure of TiO2NPs and CPM can cause increased oxidative damage in rats and damage the tissue structure of the liver and lung.

Effect of pyrethroid pesticides on the testis of male rats: A meta-analysis.

This study quantitatively evaluated the effects of pyrethroid pesticides on the testis of male rats. An extensive literature search for relevant studies was conducted on PubMed, Web of Science, Excerpta Medica Database, the Chinese National Knowledge Infrastructure, and Chinese Biomedical Literature Database. Pooled standard mean difference with corresponding 95% confidence interval was calculated via the random-effects model. I 2 was used to evaluate heterogeneity among studies. A total of 19 studies were included for analysis in our study. Results indicated that the sperm count of rats exposed to fenvalerate was lower than that of rats in control groups. The sperm count, sperm motility, and testosterone level of rats exposed to cypermethrin and deltamethrin were lower than those of rats in control groups. Moreover, the sperm morphology of rats exposed to these pyrethroid pesticides was abnormal compared with that of rats in control groups. The present meta-analysis indicates that pyrethroid pesticides decrease rat sperm count, sperm motility, and testosterone level and cause abnormal rat sperm morphology. Therefore, pyrethroid pesticides can damage the testis of male rats.

Vertically Aligned Gold Nanowires as Stretchable and Wearable Epidermal Ion-Selective Electrode for Noninvasive Multiplexed Sweat Analysis.

The noninvasive continuous analysis of human sweat is of great significance for improved healthcare diagnostics and treatment in the future, for which a wearable potentiometry-based ion-selective electrode (ISE) has attracted increasing attention, particularly involving ion detection. Note that traditional solid-state ISE electrodes are rigid ion-to-electron transducers that are not conformal to soft human skin and cannot function under stretched states. Here, we demonstrated that vertically aligned mushroom-like gold nanowires (v-AuNW) could serve as stretchable and wearable ion-to-electron transducers for multiplexed, in situ potentiometric analysis of pH, Na+, and K+ in sweat. By modifying v-AuNW electrodes with polyaniline, Na ionophore X, and a valinomycin-based selective membrane, we could specifically detect pH, Na+, and K+, respectively, with high selectivity, reproducibility, and stability. Importantly, the electrochemical performance could be maintained even under 30% strain and during stretch-release cycles without the need of extrinsic structural design. Furthermore, our stretchable v-AuNW ISEs could be seamlessly integrated with a flexible printed circuit board, enabling wireless on-body detection of pH, Na+, and K+ with fast response and negligible cross-talk, indicating considerable promise for noninvasive wearable sweat analysis.

Skin-Like Stretchable Fuel Cell Based on Gold-Nanowire-Impregnated Porous Polymer Scaffolds.

Skin-like energy devices can be conformally attached to the human body, which are highly desirable to power soft wearable electronics in the future. Here, a skin-like stretchable fuel cell based on ultrathin gold nanowires (AuNWs) and polymerized high internal phase emulsions (polyHIPEs) scaffolds is demonstrated. The polyHIPEs can offer a high porosity of 80% yet with an overall thickness comparable to human skin. Upon impregnation with electronic inks containing ultrathin (2 nm in diameter) and ultrahigh aspect-ratio (>10 000) gold nanowires, skin-like strain-insensitive stretchable electrodes are successfully fabricated. With such designed strain-insensitive electrodes, a stretchable fuel cell is fabricated by using AuNWs@polyHIPEs, platinum (Pt)-modified AuNWs@polyHIPEs, and ethanol as the anode, cathode, and fuel, respectively. The resulting epidermal fuel cell can be patterned and transferred onto skin as "tattoos" yet can offer a high power density of 280 µW cm-2 and a high durability (>90% performance retention under stretching, compression, and twisting). The results presented here demonstrate that this skin-thin, porous, yet stretchable electrode is essentially multifunctional, simultaneously serving as a current collector, an electrocatalyst, and a fuel host, indicating potential applications to power future soft wearable 2.0 electronics for remote healthcare and soft robotics.

Effect of a beta-cypermethrin and emamectin benzoate pesticide mixture on reproductive toxicity in male mice in a greenhouse environment.

With the widespread use of pesticides, the resistance to pesticides of pests has gradually increased, caused mixed pesticides to become even more widely used for practical applications. To investigate the effects of mixed pesticides on reproductive health in an occupational greenhouse environment, the greenhouse environment and the characteristics of the actual application were constructed, and then the male mice were comprehensively exposed to a mixture of the beta-cypermethrin and emamectin benzoate environmental. Additionally, the effect of the beta-cypermethrin and emamectin benzoate mixture on the reproductive health of male mice was known. The results showed that with the prolongation of exposure duration, the activities of Glutathione Peroxidase (GSH-Px), Total Superoxide Dismutase (T-SOD), Lactate dehydrogenase (LDH) and Acid phosphatase (ACP) in the testes of mice gradually decreased and the activity of Malondialdehyde (MDA) gradually increased. It was also found that the apoptosis rate of murine testicular cells increased and that DNA damage occurred with prolonged exposure duration. Therefore, it can be inferred that exposure to a mixture of the pesticides beta-cypermethrin and emamectin benzoate in the greenhouse environment may have adverse effects on the reproductive health of male mice.

Highly Stretchable and Strain-Insensitive Fiber-Based Wearable Electrochemical Biosensor to Monitor Glucose in the Sweat.

Development of high-performance fiber-shaped wearable sensors is of great significance for next-generation smart textiles for real-time and out-of-clinic health monitoring. The previous focus has been mainly on monitoring physical parameters such as pressure and strains associated with human activities. Development of an enzyme-based non-invasive wearable electrochemical sensor to monitor biochemical vital signs of health such as the glucose level in sweat has attracted increasing attention recently, due to the unmet clinical needs for the diabetic patients. To achieve this, the key challenge lies in the design of a highly stretchable fiber with high conductivity, facile enzyme immobilization, and strain-insensitive properties. Herein, we demonstrate an elastic gold fiber-based three-electrode electrochemical platform that can meet the aforementioned criteria toward wearable textile glucose biosensing. The gold fiber could be functionalized with Prussian blue and glucose oxidase to obtain the working electrode and modified by Ag/AgCl to serve as the reference electrode; and the nonmodified gold fiber could serve as the counter electrode. The as-fabricated textile glucose biosensors achieved a linear range of 0-500 µM and a sensitivity of 11.7 µA mM-1 cm-2. Importantly, such sensing performance could be maintained even under a large strain of 200%, indicating the potential applications in real-world wearable biochemical diagnostics from human sweat.

Real-Time and In-Situ Monitoring of H2O2 Release from Living Cells by a Stretchable Electrochemical Biosensor Based on Vertically Aligned Gold Nanowires.

Traditional electrochemical biosensing electrodes (e.g., gold disk, glassy carbon electrode, etc.) can undergo sophisticated design to detect chemicals/biologicals from cells. However, such electrodes are typically rigid and nonstretchable, rendering it challenging to detect cellular activities in real-time and in situ when cells are in mechanically deformed states. Here, we report a new stretchable electrochemical cell-sensing platform based on vertically aligned gold nanowires embedded in PDMS (v-AuNWs/PDMS). Using H2O2 as a model analyte, we show that the v-AuNWs/PDMS electrode can display an excellent sensing performance with a wide linear range, from 40 µM to 15 mM, and a high sensitivity of 250 mA/cm2/M at a potential of -0.3 V. Moreover, living cells can grow directly on our stretchable high-surface area electrodes with strong adhesion, demonstrating their excellent biocompatibility. Further cell stimulation by adding chemicals induced H2O2 generation, which can be detected in real-time and in situ using our v-AuNWs/PDMS platform for both natural and stretched states of cells. Our results indicate the v-AuNWs/PDMS electrochemical biosensor may serve as a general cell-sensing platform for living organisms under deformed states.

Embedding Pinhole Vertical Gold Nanowire Electronic Skins for Braille Recognition.

Electronic skins (e-skins) have the potential to be conformally integrated with human body to revolutionize wearable electronics for a myriad of technical applications including healthcare, soft robotics, and the internet of things, to name a few. One of the challenges preventing the current proof of concept translating to real-world applications is the device durability, in which the strong adhesion between active materials and elastomeric substrate or human skin is required. Here, a new strategy is reported to embed vertically aligned standing gold nanowires (v-AuNWs) into polydimethylsiloxane, leading to a robust e-skin sensor. It is found that v-AuNWs with pinholes can have an adhesion energy 18-fold greater than that for pinhole-free v-AuNWs. Finite element modeling results show that this is due to friction force from interfacial embedment. Furthermore, it is demonstrated that the robust e-skin sensor can be used for braille recognition.

Proteomes analysis reveals the involvement of autophagy in AD-like neuropathology induced by noise exposure and ApoE4.

BACKGROUND: Noise is one of the most important environmental health hazards for humans. Environmental noise or apolipoprotein ε4 (ApoE4) can cause typical Alzheimer's disease (AD)-like pathological changes, which is characterized by progressive cognitive decline and neurodegenerative lesions. Gene-environment interactions may accelerate cognitive decline and increase AD risk. However, there is limited experimental evidence regarding the underlying mechanisms of noise-ApoE4 interactions and AD, which may be closely related to AD development. METHODS: In this study, we investigated the combined effects of chronic noise exposure and the ApoE4 gene activation on hippocampus by using proteomics and differentially expressed proteins were found through performed gene ontology function and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. In addition, we assessed the changes in adult hippocampal neurogenesis and potential underlying mechanism for AD-like neuropathology. RESULTS: Relative to control rats, combined exposure of noise and ApoE4 synergistically increased the characteristic pathological amyloid ß-protein of AD-like neuropathology changes in hippocampus. The research identifies a total of 4147 proteins and 15 differentially expressed proteins in hippocampus. Furthermore, comparison of several of the diverse key pathways studied (e.g., PI3K/AKT, insulin, calpain-CDK5, and mammalian target of rapamycin (mTOR) signaling pathways) help to articulate the different mechanisms involved in combined effects of noise and ApoE4 on AD-like pathology. We verified four selected proteins, namely, eukaryotic translation elongation factor 1 epsilon 1, glycine amidinotransferase, nucleoredoxin, and tuberous sclerosis 1 proteins. Validation data shows significant effects of chronic noise and ApoE4 on the expression of four selected proteins, eukaryotic translation elongation factor 1 epsilon 1, glycine amidinotransferase, nucleoredoxin, and tuberous sclerosis 1 proteins, and mTOR and autophagy-related proteins, which share significant interaction effect of chronic noise and ApoE4. CONCLUSION: Gene-environment interactions between chronic noise and ApoE4 activate the mTOR signaling, decrease autophagy, and facilitate AD-like changes in the hippocampus. Thus, our findings may help elucidate the role of gene-environment interactions in AD development.

Boron Nitride Quantum Dots as Efficient Coreactant for Enhanced Electrochemiluminescence of Ruthenium(II) Tris(2,2'-bipyridyl).

In the present work, an enhanced and stable anodic electrochemiluminescence (ECL) was observed from a suspension of boron nitride quantum dots (BNQDs) and Ru(bpy)32+, which had a 400-fold enhancement compared with individual Ru(bpy)32+. Interestingly, different from the previous research on BNQDs as a type of optical probe, BNQDs were demonstrated as an efficient coreactant of Ru(bpy)32+-based ECL for the first time and confirmed by collecting the ECL spectra. The amino-bearing groups and the electrocatalytic effect of the BNQDs endowed them as potential coreactants for ECL of Ru(bpy)32+, and the possible mechanism of the electrode surface reaction was discussed. Several factors including electrode material, the pH of the buffer solution, and the amount of BNQDs were investigated and also further confirmed the role of the BNQDs in the proposed Ru(bpy)32+/BNQDs system. On the basis of the quenching effect between the excited state of Ru(bpy)32+ and the oxidation form of DA in the ECL system of Ru(bpy)32+/BNQDs, the ECL sensing platform for DA was successfully established. The proposed ECL system with the outstanding ECL efficiency may hold great potential in the bioanlysis because of the biocompatibility and good stability of BNQDs.

Point-of-Care Diagnoses: Flexible Patterning Technique for Self-Powered Wearable Sensors.

This paper demonstrated the fabrication of a facile, low-cost, and self-powered platform for point-of-care fitness level and athletic performance monitoring sensor using electrochemical lithography method and its application in body fluid sensing. Flexible Au/prussian blue electrode was employed as the indicating electrode, where the color change was an indication of fitness level and athletic performance. A piece of Al foil, Au/multiwalled carbon nanotubes (MWCNTs)-glucose dehydrogenase, and Au/polymethylene blue-MWCNTs-lactic dehydrogenase electrodes were used for the detection of ionic strength, glucose, and lactic acid in sweat, respectively, which allows the sensor to work without any extra instrumentation and the output signal can be recognized by the naked eyes. The advantages of these sensors are (1) self-powered; (2) readily applicable to the detection of any electroactive substance by an electrochromic material; (3) easy to fabricate via two steps of EDP; and (4) point-of-care. By assembling the energy and sensing components together through a transparent adhesive tape, the proposed self-powered wearable biosensor exhibits superior performances, indicating its broad applied prospect in the point-of-care diagnoses.

Chemiluminescence of CsPbBr3 Perovskite Nanocrystal on the Hexane/Water Interface.

All-inorganic halide perovskite CsPbBr3 nanocrystals (NCs) have attracted more attention in recent years due to the unique optical feature. To date, most of the research was mainly focused on the photoluminescence (PL) and electrochemiluminescence (ECL) of the perovskite NCs. In this work, the strong chemiluminescence (CL) emission of CsPbBr3 NCs was observed for the first time on the hexane/water interface with the assistance of ammonium persulfate-(NH4)2S2O8 as coreactant. Different coreactants were investigated to demonstrate the effect on the CL behavior and it was found that CL intensity achieved the maximum in the presence of (NH4)2S2O8. In this system, electron transfer took place on the surface of the CsPbBr3 NCs, and the excited CsPbBr3 NCs was originated from the direct chemical oxidation of (NH4)2S2O8. The CL spectrum of CsPbBr3 NCs was also collected and was consistent with their PL and ECL spectra, indicating that CsPbBr3 NCs played a role of luminophor during the CL process. The discovery of monochromatic CL of highly crystallized CsPbBr3 NCs not only extends the applications of halide perovskite materials in the analytical field but also provides a new route for the exploration of the physical chemistry properties.

Vertical Gold Nanowires Stretchable Electrochemical Electrodes.

Conventional electrodes produced from gold or glassy carbon are outstanding electrochemical platforms for biosensing applications due to their chemical inertness and wide electrochemical window, but are intrinsically rigid and planar in nature. Hence, it is challenging to seamlessly integrate them with soft and curvilinear biological tissues for real-time wearable or implantable electronics. In this work, we demonstrate that vertically gold nanowires (v-AuNWs) possess an enokitake-like structure, with the nanoparticle (head) on one side and nanowires (tail) on the opposite side of the structure, and can serve as intrinsically stretchable, electrochemical electrodes due to the stronger nanowire-elastomer bonding forces preventing from interfacial delamination under strains. The exposed head side of the electrode comprising v-AuNWs can achieve a detection limit for H2O2 of 80 µM, with a linear range of 0.2-10.4 mM at 20% strain, with a reasonably high sensitivity using chronoamperometry. This excellent electrochemical performance in the elongated state, in conjunction with low-cost wet-chemistry fabrication, demonstrates that v-AuNWs electrodes may become a next-generation sensing platform for conformally integrated, in vivo biodiagnostics.

Effects of chronic noise exposure on the microbiome-gut-brain axis in senescence-accelerated prone mice: implications for Alzheimer's disease.

BACKGROUND: Chronic noise exposure is associated with neuroinflammation and gut microbiota dysregulation and increases the risk of Alzheimer's disease (AD). Environmental hazards are also thought to be associated with genetic susceptibility factors that increase AD pathogenesis. However, there is limited experimental evidence regarding the link between chronic noise stress and microbiome-gut-brain axis alterations, which may be closely related to AD development. METHODS: The aim of the present study was to systematically investigate the effects of chronic noise exposure on the microbiome-gut-brain axis in the senescence-accelerated mouse prone 8 (SAMP8) strain. We established SAMP8 mouse models to examine the consequences of noise exposure on the microbiome-gut-brain axis. Hippocampal amyloid-ß (Aß) assessment and the Morris water maze were used to evaluate AD-like changes, 16S ribosomal RNA sequencing analyses were used for intestinal flora measurements, and assessment of endothelial tight junctions and serum neurotransmitter and inflammatory mediator levels, as well as fecal microbiota transplant, was conducted to explore the underlying pathological mechanisms. RESULTS: Chronic noise exposure led to cognitive impairment and Aß accumulation in young SAMP8 mice, similar to that observed in aging SAMP8 mice. Noise exposure was also associated with decreased gut microbiota diversity and compositional alterations. Axis-series studies showed that endothelial tight junction proteins were decreased in both the intestine and brain, whereas serum neurotransmitter and inflammatory mediator levels were elevated in young SAMP8 mice exposed to chronic noise, similar to the observations made in the aging group. The importance of intestinal bacteria in noise exposure-induced epithelial integrity impairment and Aß accumulation was further confirmed through microbiota transplantation experiments. Moreover, the effects of chronic noise were generally intensity-dependent. CONCLUSION: Chronic noise exposure altered the gut microbiota, accelerated age-related neurochemical and inflammatory dysregulation, and facilitated AD-like changes in the brain of SAMP8 mice.

High-Sensitivity Electrochemiluminescence Probe with Molybdenum Carbides as Nanocarriers for α-Fetoprotein Sensing.

Suitably designed electrochemiluminescence (ECL) carrying group acting as high-efficiency solid-state probe has attracted a lot of attention. Herein, molybdenum carbides with the two-dimensional ultrathin nanosheet structure on the surface and excellent conductivity were successfully employed as the nanocarriers for the capture of ECL reagent of luminol-capped Au nanoparticles (luminol-AuNPs). Notably, the luminol-AuNPs in the hybrid (luminol-AuNPs@Mo2C) exhibited enhanced ECL performance (∼6-fold) as compared to individual luminol-AuNPs because of the facilitated electron transfer process. Ultimately, the as-prepared ECL label was used to construct a label-free ECL immunosensor for the detection of α-fetoprotein (AFP). The immunosensor shows high selectivity and high sensitivity to AFP detection with a wide linear range of 0.1 pg·mL-1 to 30 ng·mL-1 and an extremely low detection limit of 0.03 pg·mL-1 (S/N = 3). Moreover, the fabricated ECL immunosensor exhibit satisfied performance in the practical application. This novel sensing strategy not only broadens the application of molybdenum carbides but also provides a new efficient approach to detect various biomolecules.

Enhanced Electrochemiluminescence Behavior of Gold-Silver Bimetallic Nanoclusters and Its Sensing Application for Mercury(II).

Bimetallic nanoclusters (NCs) with superior performance to that of monometallic nanoclusters have attracted extensive research interest due to the synergetic effect of the two atoms. Inspired from the silver effect on the enhanced fluorescence intensity of Au NCs, a series of bovine serum albumin-protected Au-Ag bimetallic NCs were prepared by regulating the molar ratios of HAuCl4/AgNO3 and their electrochemiluminescence (ECL) property was investigated using triethylamine as co-reactant. Notably, multifold higher efficiency was achieved with Au-Ag bimetallic NCs in reference to the monometallic nanoclusters. Moreover, the doping of Ag atoms not only made the ECL emission of the Au NCs blue shift but also decreased the peak potential and onset potential, which provided an efficient and facile way to improve the ECL behavior. Based on the ECL quenching effect of Hg2+ toward Au-Ag bimetallic NCs via the formation of metallophilic bond, an ECL sensor for Hg2+ detection was proposed with good stability and high selectivity and sensitivity. These results indicated that the as-prepared Au-Ag bimetallic NCs with enhanced ECL properties can be served as an ideal luminescent material in sensing application.

Bipolar Electrode Based Reversible Fluorescence Switch Using Prussian Blue/Au Nanoclusters Nanocomposite Film.

A highly efficient fluorescence switch system based on a closed bipolar electrode (C-BPE) system was proposed for the first time. Here, Au nanoclusters (Au NCs) were premodified on one pole of the BPE and acted as the fluorescent donor. On the basis of the spectral overlap between the absorbance of electrochromic material-Prussian blue (PB) and the fluorescence spectrum of Au NCs, fluorescence quenching ("off" state) induced by the inner filter effect was observed. Due to the electrochemical reversible redox reaction between PB and Prussian white, switching the polarity of driving voltage could easily achieve the fluorescence recovery of the Au NCs, corresponding to the "on" state. Through the reasonable design of C-BPE and optimization of driving voltage, the on-off ratio of the integrated fluorescence switch was up to 2.7 and a good fatigue resistance while performing 10 on-off cycles was obtained owing to the good stability of Au NCs and the reversible redox feature of PB. The introduction of BPE made the fluorescence switch more simple and controllable compared with the traditional three-electrode system, which will provide a new route for the design of the electrical-stimuli responsive fluorescence switch, especially for the integration of the miniaturized device.

Polydopamine Nanotubes as an Effective Fluorescent Quencher for Highly Sensitive and Selective Detection of Biomolecules Assisted with Exonuclease III Amplification.

In this work, the effective fluorescence quenching ability of polydopamine nanotubes (PDANTs) toward various fluorescent dyes was studied and further applied to fluorescent biosensing for the first time. The PDANTs could quench the fluorophores with different emission frequencies, aminomethylcoumarin acetate (AMCA), 6-carboxyfluorescein (FAM), 6-carboxytetramethylrhodamine (TAMRA), and Cy5. All the quenching efficiencies reached to more than 97%. Taking advantage of PDANTs' different affinities toward ssDNA and dsDNA and utilizing the complex of FAM-labeled ssDNA and PDANTs as a sensing platform, we achieved highly sensitive and selective detection of human immunodeficiency virus (HIV) DNA and adenosine triphosphate (ATP) assisted with Exonuclease III amplification. The limits of detection (LODs) of HIV DNA and ATP reached to 3.5 pM and 150 nM, respectively, which were all lower than that of previous nanoquenchers with Exo III amplification, and the platform also presented good applicability in biological samples. Fluorescent sensing applications of this nanotube enlightened other targets detection based upon it and enriched the building blocks of fluorescent sensing platforms. This polydopamine nanotube also possesses excellent biocompatibility and biodegradability, which is suitable for future drug delivery, cell imaging, and other biological applications.

A Nanoscale Multichannel Closed Bipolar Electrode Array for Electrochemiluminescence Sensing Platform.

In this work, we report a nanoscale multichannel closed bipolar electrode (BPE) array based on the poly(ethylene terephthalate) (PET) membrane for the first time. With our design, oxidants, coreactants, quenchers, and even biomarkers can be detected in a Ru(bpy)3(2+)/TPA (tripropylamine) electrochemiluminescence (ECL) system. The multichannel PET membrane was etched according to our desire by NaOH, and then Au nanofibers were decorated in the inner region of the channel as a BPE array. Using ECL as a signal readout, a series of targets including TPA, Ru(bpy)3(2+), dopamine, H2O2, alpha-fetoprotein (AFP), and carcino-embryonic antigen (CEA) can be detected with this device. The practical application of the proposed multichannel closed BPE array was verified in the detection of AFP and CEA in human serum with satisfying results. This kind of nanoscale device holds promising potential for multianalysis. More importantly, as the PET membrane used in this device can be etched with a desirable diameter (nano- to microscale) and different BPE array densities (ion tracks of 10(8)/cm(2), 10(6)/cm(2), 10(4)/cm(2)), our design can be served as a useful platform for future advances in nanoscale bipolar electrochemistry.