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In the time of climate change, as heat waves become a more regular occurrence, indoor thermal comfort is an important factor in day to day life. Due to such circumstances, many researchers have focused their studies on finding an effective solution that will not only enable thermal comfort, but also increase satisfaction within the indoor environment and, as a result, productivity. The fast development of the biometrical field encouraged the study focused on the investigation of how bio-markers, in combination with artificial intelligence algorithms, can be collected within an experimental setting to create a new approach for non-invasive thermal discomfort detection. The developed experimental design provides synergy between automatic facial coding, pulse, and galvanic skin response measurements via iMotions software in a controlled environment. The iMotions software has built-in machine vision algorithms, and with Shimmer sensors and a post-processing tool through Affectiva AFFDEX, is able to collect facial action data through detection of the facial muscle movements and various bio-markers. The Zero Emission Building (ZEB) Test Cell laboratory was used as the control environment and transformed to imitate an office space for the data collection campaign at NTNU in Trondheim. The given experimental design provides an opportunity to create an immense database with bio-markers that are linked to the subcortical level of the brain, indoor parameters, and direct feedback on the comfort level of occupants within an office-like environment. In total, 111 data collection sessions were registered with iMotions. The discomfort button was pressed 240 times and 1080 planned indoor comfort evaluation surveys were held during experiment. The discomfort button was pressed 49 times to indicate that participant felt discomfort due to low temperature and 52 due to high temperature. Collected data revealed a big deviation in the discomfort temperature values for experiment participants with respect to performed temperature ramps. While it is common to use the same predefined temperature range for facility management, it became clear that the complexity of the task is greater and should not be approached on a human computational level. Implementation of AI can potentially provide higher value accuracy within thermal discomfort detection and enable unique personal user experience at the workplace. [ABSTRACT FROM AUTHOR]

This paper aims at providing a small-volume expansion framework for the scattering resonances of an open cavity perturbed by small particles. The shift of the scattering resonances induced by the small particles is derived without neglecting the radiation effect. The formula holds for arbitrary-shaped particles. It shows a strong enhancement in the scattering resonance shift in the case of subwavelength particles with dipole resonances. The formula is used to image small particles located near the boundary of an open resonator which admits whispering-gallery modes. Numerical examples of interest for applications are presented. [ABSTRACT FROM AUTHOR]

A deep‐red OLED satisfying the BT.2020 standard achieved an extremely high external quantum efficiency (EQE) over 30% and long lifetime. Furthermore, a near‐infrared OLED with an emission peak around 800 nm, a maximum EQE of 7.2%, and less degradation was demonstrated. This efficiency is the best among reported near‐infrared OLEDs. [ABSTRACT FROM AUTHOR]

In this work, we develop a multi-mode microscopic hyperspectral imager (MMHI) for the detection of biological samples in transmission imaging, reflection imaging and fluorescence mode. A hyperspectral image cube can be obtained with 5 μm spatial resolution and 3 nm spectral resolution through push-broom line scanning. To avoid possible shadows produced by the high magnification objective with a short working distance, two illumination patterns are designed to ensure the co-axiality of the illumination and detection. Three experiments for the detection of zebrafish and fingerprints and the classification of disaster-causing microalgae verify the good capability and functionality of the system. Based on the detected spectra, we can observe the impacts of β-carotene and melanin in zebrafish, hemoglobin in the fingertip, and chlorophyll in microalgae, respectively. Multi-modes can be switched freely according to the application requirement and characteristics of different samples, like transmission mode for the transparent/translucent sample, reflection mode for the opaque sample and fluorescence mode for the fluorescent sample. The MMHI system also has strong potential for the non-invasive and high-speed sensing of bio or clinical samples. [ABSTRACT FROM AUTHOR]

Since 1997, scientists have been trying to utilize new non-invasive approaches for thermal discomfort detection, which promise to be more effective for comparing frameworks that need direct responses from users. Due to rapid technological development in the bio-metrical field, a systematic literature review to investigate the possibility of thermal discomfort detection at the work place by non-invasive means using bio-sensing technology was performed. Firstly, the problem intervention comparison outcome context (PICOC) framework was introduced in the study to identify the main points for meta-analysis and, in turn, to provide relevant keywords for the literature search. In total, 2776 studies were found and processed using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology. After filtering by defined criterion, 35 articles were obtained for detailed investigation with respect to facility types used in the experiment, amount of people for data collection and algorithms used for prediction of the thermal discomfort event. The given study concludes that there is potential for the creation of non-invasive thermal discomfort detection models via utilization of bio-sensing technologies, which will provide a better user interaction with the built environment, potentially decrease energy use and enable better productivity. There is definitely room for improvement within the field of non-invasive thermal discomfort detection, especially with respect to data collection, algorithm implementation and sample size, in order to have opportunities for the deployment of developed solutions in real life. Based on the literature review, the potential of novel technology is seen to utilize a more intelligent approach for performing non-invasive thermal discomfort prediction. The architecture of deep neural networks should be studied more due to the specifics of its hidden layers and its ability of hierarchical data extraction. This machine learning algorithm can provide a better model for thermal discomfort detection based on a data set with different types of bio-metrical variables. [ABSTRACT FROM AUTHOR]

The collective excitations of electrons in the bulk or at the surface, viz. plasmons, play an important role in the properties of materials, and have generated the field of "plasmonics". We report the observation of a highly unusual plasmon mode on the surface of Van der Waals heterostructures (vdWHs) of graphene monolayer on 2D transition metal dichalcogenide (Gr-TMD) substrate. Since the exponentially decaying fields of surface plasmon wave propagating along interface is highly sensitive to the ambient refractive index variations, such heterostructures are useful for ultra-sensitive bio-sensing. [ABSTRACT FROM AUTHOR]

Background/Aims: Changes in cell-to-cell communication have been linked to several secondary complications of diabetes, but the mechanism by which connexins affect disease progression in the kidney is poorly understood. This study examines a role for glucose-evoked changes in the beta1 isoform of transforming growth factor (TGFβ1), on connexin expression, gap-junction mediated intercellular communication (GJIC) and hemi-channel ATP release from tubular epithelial cells of the proximal renal nephron. Methods: Biopsy material from patients with and without diabetic nephropathy was stained for connexin-26 (CX26) and connexin-43 (CX43). Changes in expression were corroborated by immunoblot analysis in human primary proximal tubule epithelial cells (hPTECs) and model epithelial cells from human renal proximal tubules (HK2) cultured in either low glucose (5mmol/L) ± TGFβ1 (2-10ng/ml) or high glucose (25mmol/L) for 48h or 7days. Secretion of the cytokine was determined by ELISA. Paired whole cell patch clamp recordings were used to measure junctional conductance in control versus TGFβ1 treated (10ng/ml) HK2 cells, with carboxyfluorescein uptake and ATP-biosensing assessing hemi-channel function. A downstream role for ATP in mediating the effects of TGF-β1 on connexin mediated cell communication was assessed by incubating cells with ATPγS (1-100µM) or TGF-β1 +/- apyrase (5 Units/ml). Implications of ATP release were measured through immunoblot analysis of interleukin 6 (IL-6) and fibronectin expression. Results: Biopsy material from patients with diabetic nephropathy exhibited increased tubular expression of CX26 and CX43 (P

Abstract As the advanced functional materials, silver nanoparticles are potentially useful in various fields such as photoelectric, bio-sensing, catalysis, antibacterial and other fields, which are mainly based on their various properties. However, the properties of silver nanoparticles are usually determined by their size, shape, and surrounding medium, which can be modulated by various synthesis methods. In this review, the fabrication methods for synthesizing silver nanoparticles of different shapes and specific size are illustrated in detail. Besides, the corresponding properties and applications of silver nanoparticles are also discussed in this paper.

Metal nanoprobes have recently attracted board research interestinr their application in establishing sensing systems due to their unique optical, electrical, physical, and chemical properties. In comparison to gold and silver nanoprobes, analytical platform based on copper nanoprobes (Cu‐NPs) is still in the early stages of development. In this review, we focus on single‐stranded, and double‐stranded DNA capped Cu‐NPs sensing systems which have been designed for various analytes, including metal ions, anions, small molecules, biomolecules (DNA, RNA, and protein, etc.). In addition, the application of Cu‐NPs in biological labeling or bio‐imaging platforms has also been introduced and summarized. [ABSTRACT FROM AUTHOR]

The development of a novel polydopamine (PDA)-functionalized graphene nanoplatelets (GNPs)-based disposable sensor is described. The sensor was fabricated by drop-coating PDA@GNPs in polyethylene glycol (PEG) and poly(3,4-ethylenedioxythiophene (PEDOT):poly(styrenesulfonate) (PSS) aqueous suspension onto the working area of a screen-printed electrode (SPE). The final sensor, designated as PDA@GNPs/PPP/SPE, was characterized by scanning electron microscopy (SEM), Raman spectroscopy, Faradaic electrochemical impedance spectroscopy (FEIS) and cyclic voltammetry (CV). Mediated detection of hydrogen peroxide (H 2 O 2) via the redox properties of PDA was achieved. It showed excellent selectivity and sensitivity towards H 2 O 2 with a limit of detection and sensitivity of 0.55 µM (S/N = 3) and 3.0 µA mM−1 cm−2, respectively. Thereafter, glucose oxidase (GOx) was immobilized onto the electrode to develop GOx/PDA@GNPs/PPP/SPE sensor. The glucose biosensor exhibited a limit of detection of 0.25 μM (S/N = 3) and a sensitivity of 0.51 μA μM−1 cm−2; thus, proving its potential suitability for bio-sensing applications. [ABSTRACT FROM AUTHOR]

Age structure in most developed countries is changing fast as the average lifespan is increasing significantly, calling for solutions to provide improved treatments for age-related neurological diseases and disorders. In order to address these problems, a reliable way of recording information about neurotransmitters from in vitro and in vivo applications is needed to better understand neurological diseases and disorders as well as currently used treatments. Likewise, recent developments in medicine, especially with the opioid crisis, are demanding a swift move to personalized medicine to administer patient needs rather than population-wide averages. In order to enable the so-called personalized medicine, it is necessary to be able to do measurements in vivo and in real time. These actions require sensitive and selective detection of different analytes from very demanding environments. Current state-of-the-art materials are unable to provide sensitive and selective detection of neurotransmitters as well as the required time resolution needed for drug molecules at a reasonable cost. To meet these challenges, we have utilized different metals to grow carbon nanomaterials and applied them for sensing applications showing that there are clear differences in their electrochemical properties based on the selected catalyst metal. Additionally, we have combined atomistic simulations to support optimizing materials for experiments and to gain further understanding of the atomistic level reactions between different analytes and the sensor surface. With carbon nanostructures grown from Ni and Al + Co + Fe hybrid, we can detect dopamine, ascorbic acid, and uric acid simultaneously. On the other hand, nanostructures grown from platinum provide a feasible platform for detection of H2O2 making them suitable candidates for enzymatic biosensors for detection of glutamate, for example. Tetrahedral amorphous carbon electrodes have an ability to detect morphine, paracetamol, tramadol, and O-desmethyltramadol. With carbon nanomaterial-based sensors, it is possible to reach metal-like properties in sensing applications using only a fraction of the metal as seed for the material growth. We have also seen that by using nanodiamonds as growth catalyst for carbon nanofibers, it is not possible to detect dopamine and ascorbic acid simultaneously, although the morphology of the resulting nanofibers is similar to the ones grown using Ni. This further indicates the importance of the metal selection for specific applications. However, Ni as a continuous layer or as separate islands does not provide adequate performance. Thus, it appears that metal nanoparticles combined with fiber-like morphology are needed for optimized sensor performance for neurotransmitter detection. This opens up a new research approach of application-specific nanomaterials, where carefully selected metals are integrated with carbon nanomaterials to match the needs of the sensing application in question. [ABSTRACT FROM AUTHOR]

Zinc sulphide Quantum Dots (QDs) are semiconductor nanoparticles that have profound applications in medical imaging, photocatalysis and biosensing. Of late, green synthesis of ZnS QDs has emerged as an useful substitute for the routine chemical synthesis. The present study reports the biosynthesis of ZnS QDs using the fungus Aspergillus sp. under ambient conditions. In the present study, the mechanism behind the antibacterial action of the biosynthesized ZnS Quantum Dots has been explored. It was found that biogenesis using fungus has resulted in the synthesis of spherical crystalline ZnS particles of mean diameter 6.3 nm. FTIR analysis indicated the presence of active organic functional groups on the surface of the QDs. The optical and structural features of the biogenic ZnS were found to be comparable with that of the chemically synthesized quantum dots. Thereafter, the antibacterial activities of the biosynthesized ZnS QDs were observed against pathogenic bacteria. The green synthesized ZnS exhibited excellent antibacterial activity and were quantified using filter paper bioassay. Experimental evidences indicated that the antibacterial strategy relied on bacterial cell membrane disruption, leakage of the cytoplasmic contents and associated ROS mediated oxidative damages leading to bacterial cell lysis. Further, the prospects of biogenic ZnS for photodegradation of dyes and sensing of heavy metals in aqueous phase were investigated. [ABSTRACT FROM AUTHOR]

Organic electrochemical transistors (OECTs) are transducing devices that, placed in contact with an electrolyte solution, detect the ionic composition of that solution by measuring the channel current $I$. OECTs enable the streaming of continuously updated zero-to-low latency information and show, therefore, promise for being used as highly efficient biosensors. Nevertheless, apart from simple geometries, decoding such an information may be infeasible. Here, we show how $I$ can be processed to derive a reduced set of two variables that account for most of the information of a system: 1) the modulation $m$ is the current gained by the system compared to its initial value; and 2) the effective time $t_{e}$ is the time over which the response of the system stays above the 65% of its final value. $m$ and $t_{e}$ can be reported in a diagram that is akin to the state space diagrams used in thermodynamics: points in the diagram describe the state of a system at a specific time; trajectories in the diagram describe the time evolution of that system. We show that the total electric charge $Q$ exchanged by the system between two states A and B is independent on the path taken between them. This, in turn, implies that $m$ and $t_{e}$ are state variables of the system. In experiments with Solanum lycopersicum tomato plants, we show how this concept can be used to extract relevant information about a biophysical system without direct knowledge of its internal workings. [ABSTRACT FROM AUTHOR]

We present a review of field effect transistors (FET) from the point of view of their applications to label-free sensing in the era of genomics and proteomics. Here, rather than a collection of Bio-FET achievements, we propose an analysis of the different issues hampering the use of these devices into clinical applications. We make a particular emphasis on the influence of the sensor geometry in the phenomena of mass transport of analytes, which is a topic that has been traditionally overlooked in the analysis and design of biosensors, but that plays a central role in the achievement of low limits of detection. Other issues like the screening of charges by the ions in liquids with physiological ionic strength and the non-specific binding are also reviewed. In conclusion, we give an overview of different solutions that have been proposed to address all these challenges, demonstrating the potential of field effect transistors owing to their ease of integration with other semiconductor components for developing cost-effective, highly multiplexed sensors for next-generation medicines. [ABSTRACT FROM AUTHOR]

Multi-modal bio-sensing has recently been used as effective research tools in affective computing, autism, clinical disorders, and virtual reality among other areas. However, none of the existing bio-sensing systems support multi-modality in a wearable manner outside well-controlled laboratory environments with research-grade measurements. This paper attempts to bridge this gap by developing a wearable multi-modal bio-sensing system capable of collecting, synchronizing, recording, and transmitting data from multiple bio-sensors: PPG, EEG, eye-gaze headset, body motion capture, GSR, etc., while also providing task modulation features including visual-stimulus tagging. This study describes the development and integration of various components of our system. We evaluate the developed sensors by comparing their measurements to those obtained by a standard research-grade bio-sensors. We first evaluate different sensor modalities of our headset, namely, earlobe-based PPG module with motion-noise canceling for ECG during heart-beat calculation. We also compare the steady-state visually evoked potentials measured by our shielded dry EEG sensors with the potentials obtained by commercially available dry EEG sensors. We also investigate the effect of head movements on the accuracy and precision of our wearable eye-gaze system. Furthermore, we carry out two practical tasks to demonstrate the applications of using multiple sensor modalities for exploring previously unanswerable questions in bio-sensing. Specifically, utilizing bio-sensing, we show which strategy works best for playing “Where is Waldo?” visual-search game, changes in EEG corresponding to true vs. false target fixations in this game, and predicting the loss/draw/win states through bio-sensing modalities while learning their limitations in a “Rock-Paper-Scissors” game. [ABSTRACT FROM AUTHOR]

Thanks to its negative surface charge and high swelling behavior, montmorillonite (MMT) has been widely used to design hybrid materials for applications in metal ion adsorption, drug delivery, or antibacterial substrates. The changes in photophysical and photochemical properties observed when fluorophores interact with MMT make these hybrid materials attractive for designing novel optical sensors. Sensor technology is making huge strides forward, achieving high sensitivity and selectivity, but the fabrication of the sensing platform is often time-consuming and requires expensive chemicals and facilities. Here, we synthesized metal-modified MMT particles suitable for the bio-sensing of self-fluorescent biomolecules. The fluorescent enhancement achieved by combining clay minerals and plasmonic effect was exploited to improve the sensitivity of the fluorescence-based detection mechanism. As proof of concept, we showed that the signal of fluorescein isothiocyanate can be harvested by a factor of 60 using silver-modified MMT, while bovine serum albumin was successfully detected at 1.9 µg/mL. Furthermore, we demonstrated the versatility of the proposed hybrid materials by exploiting their plasmonic properties to develop liquid label-free detection systems. Our results on the signal enhancement achieved using metal-modified MMT will allow the development of highly sensitive, easily fabricated, and cost-efficient fluorescent- and plasmonic-based detection methods for biomolecules.

• Polarization dependence showed in thin gold-coated multicore fiber interferometer. • Effects of three gold layer thickness on refractometric sensitivity. • A new all-fibered platform for insulin bio-sensing starting from 10−8 g/ml. In this work, we present a supermode interferometer for biosensing application. The interferometer was fabricated with a segment of a seven-core fiber fusion-spliced to a standard single-mode fiber. We have found that when a thin gold layer was deposited on the multicore fiber (MCF) end facet, the response of the interferometer to refractive index (RI) changes was polarization dependent. The highest sensitivity to RI was achieved for a ∼10 nm-thick gold coated sample when P-polarized light was used. The gold-coated sample was later bio-functionalized and then used for insulin detection. The sensor was able to detect insulin with a concentration level of 10−8 g/ml. [ABSTRACT FROM AUTHOR]

In the time of climate change, as heat waves become a more regular occurrence, indoor thermal comfort is an important factor in day to day life. Due to such circumstances, many researchers have focused their studies on finding an effective solution that will not only enable thermal comfort, but also increase satisfaction within the indoor environment and, as a result, productivity. The fast development of the biometrical field encouraged the study focused on the investigation of how bio-markers, in combination with artificial intelligence algorithms, can be collected within an experimental setting to create a new approach for non-invasive thermal discomfort detection. The developed experimental design provides synergy between automatic facial coding, pulse, and galvanic skin response measurements via iMotions software in a controlled environment. The iMotions software has built-in machine vision algorithms, and with Shimmer sensors and a post-processing tool through Affectiva AFFDEX, is able to collect facial action data through detection of the facial muscle movements and various bio-markers. The Zero Emission Building (ZEB) Test Cell laboratory was used as the control environment and transformed to imitate an office space for the data collection campaign at NTNU in Trondheim. The given experimental design provides an opportunity to create an immense database with bio-markers that are linked to the subcortical level of the brain, indoor parameters, and direct feedback on the comfort level of occupants within an office-like environment. In total, 111 data collection sessions were registered with iMotions. The discomfort button was pressed 240 times and 1080 planned indoor comfort evaluation surveys were held during experiment. The discomfort button was pressed 49 times to indicate that participant felt discomfort due to low temperature and 52 due to high temperature. Collected data revealed a big deviation in the discomfort temperature values for experiment participants with respect to performed temperature ramps. While it is common to use the same predefined temperature range for facility management, it became clear that the complexity of the task is greater and should not be approached on a human computational level. Implementation of AI can potentially provide higher value accuracy within thermal discomfort detection and enable unique personal user experience at the workplace.

In this work, we develop a multi-mode microscopic hyperspectral imager (MMHI) for the detection of biological samples in transmission imaging, reflection imaging and fluorescence mode. A hyperspectral image cube can be obtained with 5 μm spatial resolution and 3 nm spectral resolution through push-broom line scanning. To avoid possible shadows produced by the high magnification objective with a short working distance, two illumination patterns are designed to ensure the co-axiality of the illumination and detection. Three experiments for the detection of zebrafish and fingerprints and the classification of disaster-causing microalgae verify the good capability and functionality of the system. Based on the detected spectra, we can observe the impacts of β-carotene and melanin in zebrafish, hemoglobin in the fingertip, and chlorophyll in microalgae, respectively. Multi-modes can be switched freely according to the application requirement and characteristics of different samples, like transmission mode for the transparent/translucent sample, reflection mode for the opaque sample and fluorescence mode for the fluorescent sample. The MMHI system also has strong potential for the non-invasive and high-speed sensing of bio or clinical samples.

Since 1997, scientists have been trying to utilize new non-invasive approaches for thermal discomfort detection, which promise to be more effective for comparing frameworks that need direct responses from users. Due to rapid technological development in the bio-metrical field, a systematic literature review to investigate the possibility of thermal discomfort detection at the work place by non-invasive means using bio-sensing technology was performed. Firstly, the problem intervention comparison outcome context (PICOC) framework was introduced in the study to identify the main points for meta-analysis and, in turn, to provide relevant keywords for the literature search. In total, 2776 studies were found and processed using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology. After filtering by defined criterion, 35 articles were obtained for detailed investigation with respect to facility types used in the experiment, amount of people for data collection and algorithms used for prediction of the thermal discomfort event. The given study concludes that there is potential for the creation of non-invasive thermal discomfort detection models via utilization of bio-sensing technologies, which will provide a better user interaction with the built environment, potentially decrease energy use and enable better productivity. There is definitely room for improvement within the field of non-invasive thermal discomfort detection, especially with respect to data collection, algorithm implementation and sample size, in order to have opportunities for the deployment of developed solutions in real life. Based on the literature review, the potential of novel technology is seen to utilize a more intelligent approach for performing non-invasive thermal discomfort prediction. The architecture of deep neural networks should be studied more due to the specifics of its hidden layers and its ability of hierarchical data extraction. This machine learning algorithm can provide a better model for thermal discomfort detection based on a data set with different types of bio-metrical variables.

Bioreactors hold a lot of promise for tissue engineering and regenerative medicine applications. They have multiple uses including cell cultivation for therapeutic production and for in vitro organ modelling to provide a more physiologically relevant environment for cultures compared to conventional static conditions. Bioreactors are often used in combination with scaffolds as the nutrient flow can enhance oxygen and diffusion throughout the 3D constructs to prevent the formation of necrotic cores. A variety of scaffolds have been fabricated to achieve a structural architecture that mimic native extracellular matrix. Future developments of in vitro models will incorporate the ability to non-invasively monitor the cellular microenvironment to enhance the understanding of in vitro conditions. This review details current advancements in bioreactor and scaffold systems and provides insight on how in vitro models can be augmented for future biomedical applications. [ABSTRACT FROM AUTHOR]

Highlights • Design and fabrication of polymer micro-cantilevers onto the end of standard single mode fibers using ns-laser machining Combination of sensing probe with standard optical fibers as a delivery device. • Achievement of Biotin and streptavidin binding with a minimum detectable level of 10 nM. • Detection of Listeria food pathogen with minimum detectable concentration of less than 105 cfu/ml. • New route for label-free rapid and portable biosensing platform. Abstract Micro-cantilever sensors have shown great promise in a wide range of applications including chemical medical and biological sensing. However, many of these devices are based upon a sensor ‘chip’ that requires careful alignment between the cantilever and the read-out system, which can be challenging. Furthermore, optical interrogation typically involves a bulky free-space system. Optical fiber addressed cantilevers have been reported previously in the literature and in this paper we propose techniques to design and fabricate polymer micro-cantilevers onto the end of standard single mode fibers using ns-laser machining. The cantilever will deflect and thereby observing biological binding between species of interests and activated cantilevers. Proof-of-concept experiments demonstrate that the sensor is capable of detecting Listeria food pathogen concentrations with a minimum level of less than 105cfu/ml. [ABSTRACT FROM AUTHOR]

This paper presents a low-power low-noise instrumentation amplifier (IA) for bio-potential recording. The proposed IA is based on a novel Gm-RSC structure, whose gain is determined by the transconductance (Gm) and the equivalent resistance (R) of the switched-capacitor (SC) load. The transconductance amplifier stage is based on the current-reuse telescope topology to achieve low noise at low-power dissipation. A resistor-controlled oscillator is designed to generate desirable operational frequency for SC load and to continuously tune the mid-band gain of the IA for different biomedical applications. Measurement results show that the input referred noise of the proposed IA is about 1.27μVRMS (BW=150Hz) and the noise efficiency factor is 3.3. The range of tunable gain is from 28 to 40dB. The common mode rejection ratio and power supply rejection ratio at 50Hz are 72 and 78dB, respectively. The IA consumes only 660nA current at 1.2V supply and the active area of the IA is only 0.035mm2. [ABSTRACT FROM AUTHOR]

Rapid detection techniques of pathogenic bacteria in the liquid food supply chain are of significant research interest due to their pivotal role in preventing foodborne outbreaks, and in maintaining high standards of public health and safety. Milk and dairy products are of particular interest due to their widespread consumption across the globe. In this paper, a biosensor for detecting pathogenic bacteria in milk using dextrin-capped gold nanoparticles (d-AuNP) as labels decoded at microwave frequencies is presented. The SPEL (sensing pathogens electrically in liquids) biosensor consists of a 3D printed vial and uses an RF reader and an RFID (radio-frequency identification) compatible Split Ring Resonator (SRR) based tag. The SPEL biosensor is capable of detecting bacteria at 5 log CFU/mL within 75 min, with the possibility of testing multiple concurrent samples. Detection is based on impedance loading of SRR by d-AuNP bound to pathogenic bacteria. Spectrophotometry, along with carbohydrate-functionalized magnetic nanoparticle (MNP) cell capture, is used to verify the sensitivity of the SPEL biosensor with respect to d-AuNP presence. The proof-of-concept device, along with challenges and opportunities for commercialization, are also outlined. [ABSTRACT FROM AUTHOR]

Automobiles for our roadways are increasingly using advanced driver assistance systems. The adoption of such new technologies requires us to develop novel perception systems not only for accurately understanding the situational context of these vehicles, but also to infer the driver’s awareness in differentiating between safe and critical situations. This manuscript focuses on the specific problem of inferring driver awareness in the context of attention analysis and hazardous incident activity. Even after the development of wearable and compact multi-modal bio-sensing systems in recent years, their application in driver awareness context has been scarcely explored. The capability of simultaneously recording different kinds of bio-sensing data in addition to traditionally employed computer vision systems provides exciting opportunities to explore the limitations of these sensor modalities. In this work, we explore the applications of three different bio-sensing modalities namely electroencephalogram (EEG), photoplethysmogram (PPG) and galvanic skin response (GSR) along with a camera-based vision system in driver awareness context. We assess the information from these sensors independently and together using both signal processing- and deep learning-based tools. We show that our methods outperform previously reported studies to classify driver attention and detecting hazardous/non-hazardous situations for short time scales of two seconds. We use EEG and vision data for high resolution temporal classification (two seconds) while additionally also employing PPG and GSR over longer time periods. We evaluate our methods by collecting user data on twelve subjects for two real-world driving datasets among which one is publicly available (KITTI dataset) while the other was collected by us (LISA dataset) with the vehicle being driven in an autonomous mode. This work presents an exhaustive evaluation of multiple sensor modalities on two different datasets for attention monitoring and hazardous events classification.

This paper details the design, fabrication, and characterization of highly uniform batch-fabricated sidewall etched vertical nanogap tunneling junctions for bio-sensing applications. The device consists of two vertically stacked gold electrodes separated by a partially etched sacrificial spacer layer of sputtered α-Si and Atomic Layer Deposited (ALD) SiO2. A ~10 nm wide air-gap is formed along the sidewall by a controlled dry etch of the spacer. The thickness of the spacer layer can be tuned by adjusting the number of ALD cycles. The rigorous statistical characterization of the ultra-thin spacer films has also been performed. We fabricated nanogap electrodes under two design layouts with different overlap areas and spacer gaps, from ~4.0 nm to ~9.0 nm. Optical measurements reported an average non-uniformity of 0.46 nm (~8%) and 0.56 nm (~30%) in SiO2 and α-Si film thickness respectively. Direct tunneling and Fowler–Nordheim tunneling measurements were done and the barrier potential of the spacer stack was determined to be ~3.5 eV. I–V measurements showed a maximum resistance of 46 × 103 GΩ and the average dielectric breakdown field of the spacer stack was experimentally determined to be ~11 MV/cm.

Unique chemical, physical, and biological features of carbon nanotubes make them an ideal candidate for myriad applications in industry and biomedicine. Carbon nanotubes have excellent electrical and thermal conductivity, high biocompatibility, flexibility, resistance to corrosion, nano-size, and a high surface area, which can be tailored and functionalized on demand. This review discusses the progress and main fields of bio-medical applications of carbon nanotubes based on recently-published reports. It encompasses the synthesis of carbon nanotubes and their application for bio-sensing, cancer treatment, hyperthermia induction, antibacterial therapy, and tissue engineering. Other areas of carbon nanotube applications were out of the scope of this review. Special attention has been paid to the problem of the toxicity of carbon nanotubes.

Background/Aims: Changes in cell-to-cell communication have been linked to several secondary complications of diabetes, but the mechanism by which connexins affect disease progression in the kidney is poorly understood. This study examines a role for glucose-evoked changes in the beta1 isoform of transforming growth factor (TGFβ1), on connexin expression, gap-junction mediated intercellular communication (GJIC) and hemi-channel ATP release from tubular epithelial cells of the proximal renal nephron. Methods: Biopsy material from patients with and without diabetic nephropathy was stained for connexin-26 (CX26) and connexin-43 (CX43). Changes in expression were corroborated by immunoblot analysis in human primary proximal tubule epithelial cells (hPTECs) and model epithelial cells from human renal proximal tubules (HK2) cultured in either low glucose (5mmol/L) ± TGFβ1 (2-10ng/ml) or high glucose (25mmol/L) for 48h or 7days. Secretion of the cytokine was determined by ELISA. Paired whole cell patch clamp recordings were used to measure junctional conductance in control versus TGFβ1 treated (10ng/ml) HK2 cells, with carboxyfluorescein uptake and ATP-biosensing assessing hemi-channel function. A downstream role for ATP in mediating the effects of TGF-β1 on connexin mediated cell communication was assessed by incubating cells with ATPγS (1-100µM) or TGF-β1 +/- apyrase (5 Units/ml). Implications of ATP release were measured through immunoblot analysis of interleukin 6 (IL-6) and fibronectin expression. Results: Biopsy material from patients with diabetic nephropathy exhibited increased tubular expression of CX26 and CX43 (P<0.01, n=10), data corroborated in HK2 and hPTEC cells cultured in TGFβ1 (10ng/ml) for 7days (P<0.001, n=3). High glucose significantly increased TGFβ1 secretion from tubular epithelial cells (P<0.001, n=3). The cytokine (10ng/ml) reduced junctional conductance between HK2 cells from 4.5±1.3nS in control to 1.15±0.9nS following 48h TGFβ1 and to 0.42±0.2nS after 7days TGFβ1 incubation (P<0.05, n=5). Acute (48h) and chronic (7day) challenge with TGFβ1 produced a carbenoxolone (200µM)-sensitive increase in carboxyfluorescein loading, matched by an increase in ATP release from 0.29±0.06μM in control to 1.99±0.47μM after 48hr incubation with TGFβ1 (10ng/ml; P<0.05, n=3). TGF-β1 (2-10ng/ml) and ATPγs (1-100µM) increased expression of IL-6 (P<0.001 n=3) and fibronectin (P<0.01 n=3). The effect of TGF-β1 on IL-6 and fibronectin expression was partially blunted when preincubated with apyrase (n=3). Conclusion: These data suggest that chronic exposure to glucose-evoked TGFβ1 induce an increase in CX26 and CX43 expression, consistent with changes observed in tubular epithelia from patients with diabetic nephropathy. Despite increased connexin expression, direct GJIC communication decreases, whilst hemichannel expression/function and paracrine release of ATP increases, changes that trigger increased levels of expression of interleukin 6 and fibronectin. Linked to inflammation and fibrosis, local increases in purinergic signals may exacerbate disease progression and highlight connexin mediated cell communication as a future therapeutic target for diabetic nephropathy. [ABSTRACT FROM AUTHOR]

We present our theoretical study on the design of long period fiber grating (LPFG) sensor where its add-layer sensitivity is enhanced. Add-layer sensitivity quantifies the sensitivity of the sensor to the changes taking place within few tens of nanometers around the receptor molecules. Two different methodologies: the use of dual overlay layer and tailoring of the intermodal separation between two cladding modes have been used to enhance the add-layer sensisstivity. Using coupled mode analysis, we compute several examples to carry out a detailed comparative analysis between the results obtained, focusing on the cladding mode near mode transition. [ABSTRACT FROM AUTHOR]

Versatile, simple and efficient sample preparation is desirable for point-of-care testing of emerging diseases such as zoonoses, but current sample preparation assays are insensitive, labour-intensive and time-consuming and require multiple instruments. We developed a single-tube sample preparation approach involving direct pathogen enrichment and extraction from human specimens using diatomaceous earth (DE). Amine-modified DE was used to directly enrich a zoonotic pathogen, Brucella , in a large sample volume. Next, a complex of amine-modified DE and dimethyl suberimidate was used for nucleic acid extraction from the enriched pathogen. Using our single-tube approach, the pathogen can be enriched and extracted within 60 min at a level of 1 colony formation unit (CFU) from a 1 ml sample volume in the same tube. The performance of this approach is 10–100 times better than that of a commercial kit (10 2 to 10 3 CFU/ml) but does not require a large centrifuge. Finally, we combined the single-tube approach with a bio-optical sensor for rapid and accurate zoonotic pathogen detection in human urine samples. Using the combination system, Brucella in human urine can be efficiently enriched (~ 8-fold) and the detection limit is enhanced by up to 100 times (1 CFU/ml bacteria in urine) compared with the commercial kit. This combined system is fast and highly sensitive and thus represents a promising approach for disease diagnosis in the clinical setting. [ABSTRACT FROM AUTHOR]

In this paper we report on the application of over coupled long period fibre gratings (OCLPFGs) for detecting small changes in the surrounding refractive index (SRI). In addition, the optimization of a high RI (HRI) overlay deposited over the fibre for the adhesion of biological species is described. In this study, we utilised a sol-gel-based silica-titania thin film as HRI material deposited on the grating portion using the simple and versatile dip-coating (DC) technique. The OCLPFG-based sensor has been manufactured in such a way that the resonant band retains good visibility (close to the maximum coupling condition) in the transmission spectrum even after high thermal sintering of the coating material. Three different batches of OCLPFGs were produced using different withdrawal speeds and sol viscosities. By carefully tuning both the overlay thickness during the DC process and the RI of the sol-gel material during its preparation, it was possible to bring the sensor into the so-called transition mode working region, and thus maximize the sensing performance in terms of SRI changes. All devices were characterized as optical refractometers in the RI range of interest for a bio-sensing application (from 1.33 to 1.34) and, after a suitable bio-functionalisation process, one of them was used to implement a classical receptor-analyte biosensor. [ABSTRACT FROM AUTHOR]

In this paper, we present a self-powered bio-sensing system with the capability of proximity inductive-coupling communication for supply sensing and temperature monitoring. The proposed bio-sensing system includes a biofuel cell as a power source and a sensing frontend that is associated with the CMOS integrated supply-sensing sensor. The sensor consists of a digital-based gate leakage timer, a supply-insensitive time-domain temperature sensor, and a current-driven inductive-coupling transmitter and achieves low-voltage operation. The timer converts the output voltage from a biofuel cell to frequency. The temperature sensor provides a pulse width modulation (PWM) output that is not dependent on the supply voltage, and the associated inductive-coupling transmitter enables proximity communication. A test chip was fabricated in 65 nm CMOS technology and consumed 53 μW with a supply voltage of 190 mV. The low-voltage-friendly design satisfied the performance targets of each integrated sensor without any trimming. The chips allowed us to successfully demonstrate proximity communication with an asynchronous receiver, and the measurement results show the potential for self-powered operation using biofuel cells. The analysis and experimental verification of the system confirmed their robustness. [ABSTRACT FROM PUBLISHER]

Electrografting of gold and graphene surfaces by functional p‐(N‐maleimido)phenyl groups was performed by reduction of p‐(N‐maleimido)phenyldiazonium tetrafluoroborate. The reduction was carried out using cyclic voltammetry coupled with micro-gravimetric measurements by means of electrochemical quartz crystal microbalance (EQCM). The overall deposited mass on gold was higher than on graphene. However, the Faradaic efficiency was lower on Au (14%) compared to graphene (22%) after the first potential scan. Subsequently, the maleimide functional groups have been tested for immobilization of terminal thiols using (4-nitrobenzyl)mercaptan for the functionalized graphene surface and a cysteine-modified peptide for the functionalized gold surface. The functionalization by p‐(N‐maleimido)phenyl groups and the following thiol coupling of the particular surface was proven by infrared spectroscopic ellipsometry (IRSE). In addition, the interaction of the tetrabutylammonium and tetrafluoroborate ions present in the electrolyte with the Au and graphene electrodes was investigated by EQCM and revealed less electrostatic interaction of graphene with these ions in solution compared to the metal (Au) surface. [ABSTRACT FROM AUTHOR]

In this study, we have fabricated TiO 2 nanotube arrays by the potentiostatic anodic oxidation of Ti foils in fluoride-containing electrolyte and explored them as versatile devices for biosensing applications. TiO 2 nanotubes have been chemically modified in order to bind Protein A as a specific target analyte for the optical biosensing. The obtained structures have been characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, water contact angle, fluorescence microscopy, spectroscopic reflectometry and photoluminescence. Investigations show that the prepared TiO 2 nanotubes, 2.5 μm long and 75 nm thick, can be easily and efficiently bio-modified, and the obtained structures are strongly photoluminescent, thus suitable for the label-free biosensing applications in the range of μM, due to their peculiar optical properties. [ABSTRACT FROM AUTHOR]

The purpose of this review is to survey current, emerging and predicted future biotechnologies which are impacting, or are likely to impact in the future on the life sciences, with a projection for the coming 20 years. This review is intended to discuss current and future technical strategies, and to explore areas of potential growth during the foreseeable future. Information technology approaches have been employed to gather and collate data. Twelve broad categories of biotechnology have been identified which are currently impacting the life sciences and will continue to do so. In some cases, technology areas are being pushed forward by the requirement to deal with contemporary questions such as the need to address the emergence of anti-microbial resistance. In other cases, the biotechnology application is made feasible by advances in allied fields in biophysics (e.g. biosensing) and biochemistry (e.g. bio-imaging). In all cases, the biotechnologies are underpinned by the rapidly advancing fields of information systems, electronic communications and the World Wide Web together with developments in computing power and the capacity to handle extensive biological data. A rationale and narrative is given for the identification of each technology as a growth area. These technologies have been categorized by major applications, and are discussed further. This review highlights:Biotechnology has far-reaching applications which impinge on every aspect of human existence.The applications of biotechnology are currently wide ranging and will become even more diverse in the future.Access to supercomputing facilities and the ability to manipulate large, complex biological datasets, will significantly enhance knowledge and biotechnological development. [ABSTRACT FROM PUBLISHER]

Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly (styrene sulfonate) (PSS) has a variety of chemical and biomedical applications. Additionally, chitosan has been extensively used in industrial and medical fields. However, whether chitosan could be incorporated into conducting polymers of PEDOT/PSS is not clear. In this study, the PEDOT/PSS/chitosan coatings were electrochemically polymerized on the surface of 0.5 mm platinum (Pt) electrodes and the properties of electrochemical cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) of the PEDOT/PSS/chitosan-coated electrodes were investigated. Furthermore, PEDOT/PSS/chitosan-coated electrodes used for electrochemical bio-sensing, using dexamethasone (Dex) as a model bio-sensing material, were examined. The results demonstrated that PEDOT/PSS/chitosan-coated electrodes were stable in phosphate-buffered saline (PBS) solution. The electrochemical CV curve areas, reflecting the charge delivery capacity, and the EIS of the PEDOT/PSS/chitosan-coated electrodes were sensitive to Dex, and the good linearity can be obtained between CV curve areas, the EIS and the concentration of Dex. In addition, electrochemical sensitivity of the PEDOT/PSS/chitosan-coated electrodes to Dex was much higher than ultraviolet (UV) spectroscopy detection. All these results revealed that the PEDOT/PSS/chitosan-coated electrodes can be electrochemical polymerized and used for electrochemical bio-sensing. [ABSTRACT FROM AUTHOR]

Through a numerical study, we proposed and demonstrated that the one-dimensional periodic plasmonic-grooves (1D-PPG) can give rise to a super chiral field inside grooves under normal illumination with off-groove linear polarization. The handedness of the optical chirality of chiral field can be reversed by modifying the incident polarization angle from + 45° relative to groove's period direction to its mirror-symmetrical angle −45°. This makes possible a novel sensing scheme that utilize this polarization-dependent local chiral field for circular dichroism detecting; meanwhile, the dielectric environment-sensitive plasmonic resonance of 1D-PPG can be employed for refractive index sensing. This dual-sensing strategy offers great potential for low-cost chirality sensing for chiral molecules. [ABSTRACT FROM PUBLISHER]

Nano-apertures are known as interesting structures for biomedical sensing, spectroscopy, optical imaging, and electrical field manipulating. Recently, different shapes of these nanoapertures simulated based on full-wave time methods like FDTD (Finite Difference Time Domain) or FIT (Finite Integration Technique) for improving the electrical field, obtaining multi-band characteristic and polarization independence. In addition, researches show the importance of Graphene and nanoparticles for amending the nanoaperture. So, this paper discusses various topologies and arrangements of the nanoapertures and their application for biosensing in the mid-infra-red spectrum. Moreover, the background physics of the nanoaperture is considered as a basic factor for describing the elements' effect and their interactions. The fabrication processes of the nanoaperture and measurement techniques are described. Obviously, the shape of the aperture is a considerable factor for achieving multi-band features and designing a polarizer for converting the linear to circular polarization. Thus, these Nano-apertures have considered as the metasurface and chiral structure. [Display omitted] [ABSTRACT FROM AUTHOR]

We overview an approach to providing automated three-dimensional (3D) sensing and recognition of biological micro/nanoorganisms integrating Gabor digital holographic microscopy and statistical sampling methods. For 3D data acquisition of biological specimens, a coherent beam propagates through the specimen and its transversely and longitudinally magnified diffraction pattern observed by the microscope objective is optically recorded with an image sensor array interfaced with a computer. 3D visualization of the biological specimen from the magnified diffraction pattern is accomplished by using the computational Fresnel propagation algorithm. For 3D recognition of the biological specimen, a watershed image segmentation algorithm is applied to automatically remove the unnecessary background parts in the reconstructed holographic image. Statistical estimation and inference algorithms are developed to the automatically segmented holographic image. Overviews of preliminary experimental results illustrate how the holographic image reconstructed from the Gabor digital hologram of biological specimen contains important information for microbial recognition.