Heongkyu Ju, Than Thi Nguyen
We study the optical coupling between excited state quantum dots (QDs) CdSe/ZnS and fiber surface plasmon polariton at visible wavelengths. We use the bimetal coated fiber core of multimode optical fiber to excite the surface plasmons. QDs are then immobilized on the bimetallic film surface for the coupling between QDs and surface plasmons. We employ a ultraviolet-visible (UV_VIS) spectrophotometer to examine the absorbance peak shift due to the presence of QDs which are excited by a white light source. In contrast to the previous report that showed the red shift due to light absorbing molecules immobilized on metal surface, we observe the blue shift of the plasmonic spectral resonance due to the presence of QDs adsorbed on metal surface. To explain the blue shift, we invoke the negative change in refractive index stemming from emission/gain properties of the excited QDs in the context of Kramers-Kronig relation. Interestingly, magnitude of such blue shift exhibits the oscillatory feature as a function of spectral difference between the QD-free surface plasmon resonance wavelength and the QD emission wavelength of 560 nm. This study may contribute to a better understanding of QD involving plasmonic devices that can find an use in application in biomedical and environmental sensor platforms.
Luciana P. Toralles
L-asparaginase, a bacterial amidohydrolase enzyme, is one of the most employed drugs in the course of Acute Lymphoblastic Leukaemia (LLA) and other lymphoid neoplasms treatment. However, the immunological inactivation of the enzyme may go unnoticed by the side effects caused by cancer treatment. This work reports an alternative method to detect L-asparaginase activity using an optical biosensor traduced by a power sign. The biosensor was composed of monodisperse gold nanoparticles synthesized with amino acid asparagine as a reducing, stabilizing and functionalizing agent. Facile colorimetric assays was applied in order to ensure stable gold nanoparticles were formed. In this study, the detection of L-asparaginase was successfully performed by the aggregation and red-shifting of the surface plasmon resonance (SPR) of nanoparticles when both substances were together for 30 minutes. The colour changes observed were quantified by a linear and reproducible power sign. The enzyme proved to have a higher capacity of disestablish gold nanoparticles functionalized with asparagine when submitted to temperature of 37oC, regardless of asparagine concentration used in the synthesis. The results suggests a positive effect of ammonia ions produced by the depletion of asparagine in aspartic acid on such disestablishment of gold nanoparticles. Theses outcomes lead us to assume that gold nanoparticles functionalized with asparagine is a promising biosensor for detection of L-asparaginase activity during LLA treatment.
Jean Pierre Ndabakuranye
Bilirubin is clinically confirmed as a biomarker for liver health and has been utilized for assessing the prognosis of cirrhosis. Optical and chemical methods have been utilized to determine bilirubin levels in the blood. Whilst optical methods offer real-time monitoring, are handy and immune to infection among other substantial benefits, measurements may not be practical in some instances owing to the instrument complexity and space requirements. In this paper, we investigate the feasibility of using the dual wavelength technique with the aim of miniaturizing the setup. Our experiments were performed using blood phantoms within the pathological range projected from a healthy person to a cirrhotic patient (0.15 - 30 mg/dL). Results show a high sensitivity of bilirubin in blood phantoms with a larger predictive accuracy at higher bilirubin concentrations. This may provide an alternative means of determining blood bilirubin levels mostly for cirrhotic patients.
In this work, nickel nanoparticles (NiNPs) and graphene oxide (GO) were synthesized and characterized independently using UV-Vis, FTIR, high resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques. Then, a new glassy carbon electrode modified with electrochemically reduced graphene oxide decorated with nickel nanoparticles (NiNPs/ERGO/GCE) was constructed by electrodeposition. The novel platform, NiNPs/ERGO/GCE, was characterized using SEM, electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). SEM analysis clearly revealed efficient incorporation of NiNPs into the graphene sheets on the surface of the electrode. The prepared platform was used for the determination of diclofenac (DIC), a nonsteroidal antiinflammatory drug (NSAID). A significant enhancement in the peak current response for DIC was observed at the composite modified electrode compared to the unmodified electrode. The NiNPs/ERGO composite modified electrode demonstrated excellent square wave voltammetric response towards the determination of DIC in the working range of 0.25Ô??125 μM. The limit of detection (LOD) and limit of quantification (LOQ) of the proposed method was found to be 0.09 and 0.3 μM, respectively. The developed sensor was validated successfully for real sample analysis in pharmaceutical formulation and human urine samples with good recovery results. The proposed sensor also displayed good repeatability, reproducibility, longterm stability and selectivity towards potential interferents. Hence, it is a promising material for electrochemical sensing of diclofenac and other similar drugs and biologically active compounds in real samples.
Olafare Oluwumi Olajiire
There has been a tremendous success in healthcare delivery system worldwide at various points of care and other areas with the help of Biosensors in diagnosing and test equipment. On many occasions, the bioreceptor will have to come in contact with the substance which the value is to be measured9analyte) and the resultant effect that is sensed by the transducer becomes the result. There is no doubt that the process will be achieved over time, of which some of the patients cannot be attended to until the test results are ready. With the outbreak of deadly contagious diseases in recent times e,g Ebola and COVID 19, emphases should be laid on “NO CONTACT BIOSENSORS’. Though there is a breakthrough in the aspect of temperature measurement via infrared thermometers, despite that, much can still be done in determining an infection in the human body without making any contact with the person. This method will reduce the rate at which the results come out delayed. In the quest of achieving safe healthcare delivery worldwide, touchless biosensors are the solution in other to curb deadly diseases spread and also to protect the healthcare practitioners worldwide.
Conference Series LLC Ltd successfully hosted its premier 14th International Conference & Exhibition on Biosensors & Bioelectronics during September 28, 2020 in Vancouver, Canada. The conference brought together a broad spectrum of the Biosensors and Bioelectronics education community, educators from research universities with their programs and state colleges from across the world, as well as representatives from industry and professional environmental societies.
The 14th International Conference & Exhibition on Biosensors & Bioelectronics was based on the theme “Future trends development and new intervention in biosensors technologies”. The conference was greeted by the honourable guest James C.M. Hwang, IEEE - Distinguished Microwave Lecturer, Cornell University, USA and energized by;
Plenary Presentations on:
Our special thanks to supporting association is;
Kuwait Journal of Science and Engineering (KJSE, ISSN: 1024-8684), which has been in publication by the Academic Publication Council of Kuwait University since 1974, we are now publishing Kuwait Journal of Science (KJS) as an independent new Journal catering exclusively to a wide community of professionals in various disciplines of science.
Biosensors & Bioelectronics 2020 is known for uplifting the future of Biosensors & Bioelectronics by encouraging students and fellow researchers to present their work through Young Research Forum and Poster Presentations. Students participated with great zeal and the best researches were awarded for their efforts and outstanding contribution.
Last but not the least Conference Series LLC Ltd wishes to acknowledge with its deep sincere gratitude to all the supporters from the Editorial Board Members of our Open Access Journals, Keynote Speakers, Honourable Guests, Valuable speakers, Poster presenters, students, delegates and special thanks to the Media partners for their promotion to make this event a huge success.
With the enormous feedback from the participants and supporters of Biosensors & Bioelectronics 2020, Conference Series LLC Ltd is glad to announce its 15th International Conference & Exhibition on Biosensors & Bioelectronics (Biosensors & Bioelectronics 2021) from October 22-23, 2021 at Montreal, Canada.
James C.M. Hwang
Microwave is not just for cooking, smart cars, or mobile phones. We can take advantage of the wide electromagnetic spectrum to do wonderful things that are more vital to our lives. For example, microwave ablation of cancer tumor is already in wide use, and microwave remote monitoring of vital signs is becoming more important as the population ages. This talk will focus on a biomedical use of microwave at the single-cell level. At low power, microwave can readily penetrate a cell membrane to interrogate what is inside a cell, without cooking it or otherwise hurting it. It is currently the fastest, most compact, and least costly way to tell whether a cell is alive or dead. On the other hand, at higher power but lower frequency, the electromagnetic signal can interact strongly with the cell membrane to drill temporary holes of nanometer size. The nanopores allow drugs to diffuse into the cell and, based on the reaction of the cell, individualized medicine can be developed and drug development can be sped up in general. Conversely, the nanopores allow strands of DNA molecules to be pulled out of the cell without killing it, which can speed up genetic engineering. Lastly, by changing both the power and frequency of the signal, we can have either positive or negative dielectrophoresis effects, which we have used to coerce a live cell to the examination table of Dr. Microwave, then usher it out after examination. These interesting uses of microwave and the resulted fundamental knowledge about biological cells will be explored in the talk.
In this paper, we demonstrate a novel microscale surface reconstruction technology by Structure from Motion (SfM) for biological applications. Demands in 3D surface reconstruction of microscale parts for biological applications is ever increasing for molecular design, microscale geno/phenotyping, etc. In microscale photogrammetry, the confocal microscopic imaging technique has been the dominant trend. We propose a novel method to construct a 3D shape in microscale with less size limit of an object. Recently, the surface from motion (SfM) demonstrated reliable 3D reconstruction for macroscale objects. In this paper, we discuss the results of a novel micro-surface reconstruction method using the Surface from Motion in microscale. The proposed Micro SfM technique utilizes the photometric stereovision via microscopic photogrammetry. The main challenges lies in the scanning methodology, ambient light control, and light conditioning for microscale objects. Experiments with light sensitive aspects of the SfM in microscale has been shared and will be addressed in the paper.
Virgin coconut oil (VCO) is costly, and due to this reason, the marketers opt for adulteration with coconut oil. Diglyceride is the only parameter in VCO which can be used to identify adulteration with coconut oil. The existing analytical techniques used to detect the diglyceride content are based on chromatographic techniques, Nuclear Magnetic Resonance (NMR) and other spectroscopic methods. However, these methods are complicated, time-consuming. Hence, an enzyme-based amperometric biosensor may be the feasible solution to determine the diglyceride content in VCO. A multi enzyme-based amperometric biosensor was developed using a three-electrode type system. The characterization study of the immobilized working electrode was done using a Scanning Electron Microscope (SEM) and cyclic voltammetry. The working electrode process parameter like potential, % glutaraldehyde, gelatin concentration, BSA concentration and pH of the buffer has been optimized. The empirical relationship was developed between the diglyceride and output current. Different ratios of adulterated samples were taken, and the validation of the biosensor was done using HPLC method. The maximum response was found at the potential of -0.4V with 2.5%gluteraldehyde and 45 mg of gelatin at pH 7.0. Linear empirical relation developed was found to have a coefficient of determination (R2) =0.99. The validation study showed no significant difference at 95 % confidence level. The precision (CV%) was found to be 0.15±0.56 and 0.1±0.32 for the first day and seventh day, respectively. The detection limit was found in the concentration range from 2ppm to 1200 ppm of diglyceride with a detection time of 10 seconds per samples. Hence, the developed biosensor can be used to evaluate the adulteration in VCO and was observed to be reused for about 15 days.
In the current technologic era biosensors are being used largely in different fields of application. Current research trends focus on the invention of a portable detection system with high sensitivity, accuracy, repeatability, and other criteria relevant to the applications. From all the existing biosensors, Surface plasmon resonance (SPR) sensing technology has received continuous attention due to its advantage of a high-sensitivity, label-free, and fast response time. Although the SPR sensing technique being a legend in the sensor community, currently the temperature of the sample needs to be carefully maintained and controlled because the SPR signal varies with temperature. This gives a huge challenge in the application whether the SPR sensor senses only the biological reaction or it detects also the temperature change in the sample. Taking all the challenges into account we have developed a novel SPR sensor design having multi SPR channels allowing to modulate the temperature of each channel preciously in real-time independent to the other channels by using joules effect. We have experimentally demonstrated that the temperature modulation of the SPR channel by Joules heating is reliable and enables the SPR sensor system to still being portable and user-friendly.
Geraldine Isamari Silva Galindo
In recent decades, the importance of catalytic processes in various areas of application has brought about the optimization of various materials to provide systems with higher reaction rates, especially in the construction of nonenzymatic glucose biosensors, due to the high demand of continuous glucose monitoring; currently, modern glucose biosensors are based on heterostructures of various materials. It has been demonstrated that it is possible to improve catalysis processes by adding supports, controlling their physical and chemical synthesis properties. The objective is that the main catalysis process must be carried out on a support that facilitates the transfer of electrons between the catalytic material and itself, providing stability to the particles that carry out the catalysis processes, and promoting the performance of catalytic materials, thus reducing costs in fabrication, since most of them are high-cost noble metals such as gold and platinum. TiO2 has demonstrated to be a great material for the construction of the supports due to its physical and chemical stability in an alkaline and acid environment and its low cost of mass production. In this work is presented the methodology to synthesize TiO2 anatase supports electrodes by Pechini method and its morphological and structural characterization; it is also presented the electrochemical characterization which includes the behavior of the electrodes at different pH conditions, the study of selectivity and sensitivity in the presence of glucose concentrations and possible interferents in non-invasive fluids as urine, and the reproducibility and stability of the electrodes by techniques as cyclic voltammetry and chronoamperometry.
FRET-based sensors turn on /off on the target recognition is a rapid, sensitive and specific technique to detect different targets. Graphene and its composite for the quenching of fluorescent in FRET-based homogenous assays have been reported in many studies. Graphene/graphene composites are efficient energy transducers in FRET-based biosensors and repeatedly used in many studies up till now. In many fluorescent assays, these are used to quench the fluorescence of labelled single-stranded DNA when these labelled strands (DNA/RNA) are attached to the surface of quenchers. Upon getting high affinity and specific target the quenched labelled strands detached from the quencher to get bind to the relevant target. Here in this study, we labelled both ends of the aptamer with the fluorophores of two different wavelengths and observed under fluorescence microscope. To study quenching and restoration of fluorescence on a highly specific end of the aptamer. The whole study observed under the fluorescence microscope. Fluorescence –quenching – the restoration of fluorescence is followed by attachment of aptamer onto the quenchers surface and restoration of fluorescence when it detaches from rGO to attach with the target. Graphene oxide prepared by a hydrothermal process in our laboratory. To enhance energy transduction we reduced the graphene oxide surface. In this study, we proposed the binding of aptamer onto the surface of quencher is not all due to π-bond stacking but involved electrostatic attractions more dominantly. Reduced surface allows the restoration of fluorescence more efficiently. We used thrombin because of the high specification to its 15-mer DNA oligonucleotideMoreover, we also open the clinical aspects of such studies and their reliability to use these assays in clinical, industrial and laboratory applications.
We are investigating the use of mutual projected capacitive touchscreens as a label-free sensing technique. It is projected that by 2021 the number of users of capacitive touchscreen-based mobile devices will have grown to 3.8 billion people worldwide, a 52% increase within just five years. Smartphone penetration is especially expanding amongst developing countries and has attracted attention for collecting a sensor’s readout or interpreting sensed data in low-cost healthcare applications. In the medical technology sector, in-vitro diagnostics is the leading growth area and anticipated applications include biosensors will allow monitoring of drinking water quality or measurement of physiological parameters such as blood glucose levels. Here we report on the benefits and challenges of using the capacitive touchscreen for biosensing studies, a component of the mobile device often neglected in the literature. Capacitive fringe fields project above the touchscreen’s glass surface to sense and interact with a stylus or finger. Instead, we examine interactions with fluid samples and specifically sensing the presence of electrolytes. This is carried out by studying the polarisation properties of electrolyte samples in response to different electrical perturbation frequencies up to the megahertz regime. Initial results show a linear response for static capacitance measurements of low ionic concentrations below 200 µM of sodium, magnesium, calcium or potassium chloride. This has potential to directly transfer to human sweat sensing for monitoring of chronic kidney dysfunction and opens the door to exploring more complex biosensing with capacitive touchscreen displays.
Introduction: Ovulatory disorders, such as Polycystic Ovarian Syndrome are a common cause of infertility in women. The hormones relevant to ovulatory disorder diagnosis are present in healthy women and the concentration of these hormones in urine varies throughout the menstrual cycle, over the course of a woman’s life, and are affected by a variety of other lifestyle and medical factors. Objective: Characterize the performance of a portable giant magnetoresistive (GMR) biosensor in measuring the concentration of several urinary hormones related to ovulatory disorders in women. Participants: 5 women participated over the course of 28 days. Methods: Participants provided a brief medical and menstural history upon enrollement into the study. Over the course of the study, the concentrations of lutenizing hormone (LH) and pregnanediol-3-glucuronide (PDG) in first morning urine were measured by prototype GMR platforms and commercially available EIA. Urinalysis, creatinine measurements and biotin concentrations were also gathered on each sample. Results: forethcoming. Conclusions: GMR biosensor offers a promising method for quantitative measurement of LH in point of care format. Further assay development is indicated, especially for PDG. Biotin in urine, presumably from supplementattion appears to affect performance of GMR assay utilizing biotinylated antibodies.
Changing lifestyles has rendered human beings more prone to dietary deficiencies. One of such prevalent deficiencies is vitamin D, a vitamin extremely important for the bone homeostasis. The deficit of vitamin D has been observed in individuals ranging over all age groups however, the population under threat involves, infants, pregnant women, women in post-menopausal age, old age people, and individuals suffering from autoimmune bone related disorders. Thus, the detection of vitamin D has become the 5th most popular testing in diagnostics accounting for approximately $ 605.9 million worldwide in the year of 2018.
Currently, vitamin D testing is being done by the use of techniques that involve sophisticated instrumentation and skilled labor thus restricting the feasibility of testing to modernized diagnostic laboratories in urban areas. In order to make the testing available to the population in the developing countries, we have designed a cost-effective and user-friendly solution in the form of an enzyme coupled impedance based portable sensor for the detection of vitamin D.
The device is based on the in-vivo activation process of vitamin D that takes place via oxidation of 25-dihydroxyvitamin D3 to 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3] by enzyme CYP27B1. The D detect involves electrode immobilized with CYP27B1 that reacts with vitamin D in the blood sample and the interaction leads to oxidation of vitamin D. The interaction leads to a change in impedance that is being amplified and detected with the help of portable potentiostat. The D detect serves as a simple and cost effective point of care diagnostic for vitamin D.