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Mycotoxins are toxic secondary metabolites naturally produced by fungi. They can cause various kinds of acute and chronic diseases in both humans and animals since food usually contains trace amounts of mycotoxins. Thus, it is important to develop a rapid and sensitive technique for mycotoxin detection. Except for the original and classical enzyme-linked immunosorbent assays (ELISA), a series of biosensors has been developed to analyze mycotoxins in food in the last decade with the advantages of rapid analysis, simplicity, portability, reproducibility, stability, accuracy, and low cost. Nanomaterials have been incorporated into biosensors for the purpose of achieving better analytical performance in terms of limit of detection, linear range, analytical stability, low production cost, etc. Gold nanoparticles (AuNPs) are one of the most extensively studied and commonly used nanomaterials, which can be employed as an immobilization carrier, signal amplifier, mediator and mimic enzyme label. This paper aims to present an extensive overview of the recent progress in AuNPs in mycotoxin detection through ELISA and biosensors. The details of the detection methods and their application principles are described, and current challenges and future prospects are discussed as well.

The presence of various combinations of adjacent colors within polymorphic species’ color pattern could have a major impact on mate choice. We studied the role of pattern geometry in predicting mate choice in guppies using boundary strength analysis (BSA). BSA estimates the visual contrast intensity between two adjacent color patches (ΔS) weighted by the lengths of the boundaries between these adjacent color patches. We measured both the chromatic (hue and saturation) and achromatic (luminance) ΔS for each pair of adjacent patches. For each male’s color pattern, we measured BSA as both mean (mΔS) and coefficient of variation (cvΔS) of all ΔS weighted by their corresponding boundary lengths. We also determined if specific color patch boundaries had an impact on female preferences and whether these predicted overall male contrast (mΔS). We found that males with a higher mΔS were more attractive to females and that six boundaries containing either fuzzy black or black as one of the pair colors significantly affected female preferences, indicating that 1) females favored highly conspicuous males and 2) melanin-based patches could be used as a signal amplifier, not only for orange but for other colors.

We report a portable and highly sensitive Hg2+ nanosensor, where the CuS nanozyme functions as an Hg2+ recognition unit, a Hg2+ enrichment/preconcentration carrier, and a signal amplifier/output unit. The as-designed enrichment-detection integration strategy is customizable and endows the sensor with both a wide detection range from 50 ppt to 400 ppb and a high sensitivity with a minimum detectable Hg2+ concentration of 50 ppt. In order to make the Hg2+ nanosensor portable and cost-effective, a commercial RGB sensor is employed here in conjunction with the Hg2+-dependent colorimetric reaction. More importantly, the as-developed Hg2+ nanosensor is feasible for analysis of real samples with satisfactory accuracy (deviation

A single-atom metal doped on carbonaceous nanomaterials has attracted increasing attention due to its potential applications as high-performance catalysts. However, few studies focus on the applications of such nanomaterials as nanotheranostics for simultaneous bioimaging and cancer therapy. Herein, it is pioneeringly demonstrated that the single-atom Gd anchored onto graphene quantum dots (SAGd-GQDs), with dendrite-like morphology, was successfully prepared. More importantly, the as-fabricated SAGd-GQDs exhibits a robustly enhanced longitudinal relaxivity (

As the most abundant protein in blood, human serum albumin (HSA) is usually regarded as an interferent in clinical molecular diagnosis. Herein, we report that HSA is an endogenous signal amplifier for the detection of the prostate-specific antigen (PSA) in human plasma. This is the first study to utilize intrinsic biological components as the signal amplifier in blood tests.

We have developed and demonstrated a polarisation-maintaining single-mode ytterbium-doped fibre for light amplification at a wavelength near 0.976 μm in an all-fibre configuration. A distinctive feature of the proposed fibre design is low losses due to fusion splices with standard single-mode fibre having a core diameter of 10 μm, which has made it possible to produce an all-fibre small-signal amplifier with a gain threshold near 3 W and a differential pump-to-signal conversion efficiency of 9.8 % in the saturation regime. The proposed amplifier has been shown to be well-suited for small-signal amplification. In particular, at an input signal power near 1 mW and a gain of 20 dB, the ratio of the amplified signal to the integrated luminescence intensity near 0.976 μm exceeds 20 dB. A 40-dB gain has been demonstrated for an ultrasmall signal of ∼10-μW power.

An electrochemiluminescence (ECL) sensor was constructed with graphitic carbon nitride nanosheets (g-C3N4 NSs) as the luminophor and multi-walled carbon nanotubes (MWCNT) as signal amplifier. It wa...

A bio-sensor is composed of six elements which include bio-receptor, transfusion element, chemically activeinterface, signal amplifier, signal processor and display. The analyze binds to the immobilized biologicalmaterial and forms a product. The product linked change is then converted by the transducer into electricsignals which can be amplified and measured. Oral fluid bio-sensors have the advantages of easy accessibilityand noninvasive sample collection, making them a novel method in disease diagnostics. However, itslimitations such as less sensitivity and specificity are overcome by the advent of new technologies such asmicrofluidics and nanofluidics. This review article discusses the concepts and applications of biosensors inthe field of dentistry.

In the present work, a highly sensitive sandwich-type electrochemical immunosensor of carcinoembryonic antigen (CEA) was developed by preparing N-doped hollow mesoporous nanocarbon spheres/gold hybrids (NHMN/Au) hybridsas sensing platformand Au/ferrocene (Au/Fc) as signal amplifiers. The large surface area and high conductivity as well as good biocompatibility of NHMN/Au can increase the loading of primary antibody (Ab

Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.11.13 "Прилади і методи контролю та визначення складу речовин" – Національний технічний університет "Харківський політехнічний інститут". Дисертація присвячена розробці нового методу та засобів для забезпечення ультразвукового імерсійного контролю з підвищеною чутливістю щодо виявлення внутрішніх дефектів мінімального розміру. Виконано аналітичний огляд та аналіз сучасних засобів і методів неруйнівного контролю та діагностики залізничних осей та заготовок до них. При цьому розглянуто вплив завад різного типу, технічний рівень приладів і установок для контролю залізничних осей, схемотехнічних рішень засобів їх живлення, прийому з виробів ультразвукових імпульсів, визначені відомі переваги, недоліки та можливості їх використання в дослідженнях і розробках. В результаті аналізу інформаційних джерел встановлено, що ультразвукові контактний та імерсійний методи мають свої переваги і недоліки при виявленні внутрішніх дефектів і оцінки структури сталі залізничних осей та заготовок для їх виготовлення. Технічні протиріччя для кожного з них диктують необхідність виконання досліджень вказаних методів з наступним їх вирішенням. У зв’язку з зростанням вимог до якості залізничних осей показана необхідність підвищення чутливості ультразвукової дефектоскопії за рахунок калібрування приладу контролю за моделями дефектів меншого розміру, наприклад плоскодонного відбивача діаметром 1 мм і більше замість 3 мм і більше. Для забезпечення високої чутливості щодо виявлення мінімальних дефектів необхідно розробити методи і засоби їх реалізації. Визначені та обґрунтовані напрямки дисертаційного дослідження. Визначено фізичну модель контролю виробу в імерсійному варіанті, за результатами аналізу якої визначено мінімальну товщину шару імерсійної рідини між суміщеним ПЕП і поверхнею. Ця товщина повинна бути більше просторової тривалості ультразвукового імпульсу рСt (де р С – швидкість розповсюдження поздовжніх хвиль в рідині; t – тривалість імпульсу в часі). Виконано розрахунок мінімальної товщини шару імерсійної рідини між суміщеним ПЕП і поверхнею заготовки залізничної осі, яка повинна складати не менше 46 мм при діаметрі залізничної осі 170 мм. Розроблено фізико-математичну модель контролю залізничної осі в імерсійному варіанті. Виконано теоретичний розрахунок ультразвукового тракту при контролі залізничної осі прямим перетворювачем при відбитті ультразвукових імпульсів від моделей дефектів у вигляді плоскодонних відбивачів різного діаметру з врахуванням загасання сигналів в імерсійній рідині та у матеріалі залізничної осі, а також втрат енергії імпульсів на границі розподілу рідина/метал за рахунок заломлення на криволінійній поверхні та трансформації. Встановлено однозначний зв’язок між розміром дефекту і частотою ультразвукових коливань, що говорить про необхідність встановлення раціонального значення частоти ультразвукових коливань при виявленні моделі дефекту заданого нормативно-технічною документацією на контроль. Вирішено питання раціонального вибору тривалості ультразвукових імпульсів живлення ПЕП, направленого на підвищення чутливості контролю. Доказано, що можливо суттєво підвищити чутливість контролю за рахунок збільшення тривалості ультразвукових імпульсів. Такий підхід обумовлений концентрацією енергії сигналів у вузькому діапазону спектру та широкими можливостями фільтрації корисного сигналу від завад. Доцільно вибирати тривалість імпульсів не менше 3…5 періодів частоти заповнення сигналу. Проте, використовувати імпульси значної тривалості не доцільно, оскільки при цьому збільшується «мертва» (не контрольована) при поверхнева зона металу. Теоретично і експериментально доказано, що чутливість ультразвукового імерсійного контролю залізничних осей можливо підвищити за рахунок живлення п’єзоелектричних перетворювачів пакетними імпульсами струму з заданими частотою заповнення і часовою тривалістю. Встановлено, що для забезпечення достатньої чутливості ультразвукового імерсійного контролю залізничних осей (виявлення внутрішніх дефектів з ефективним розміром, що відповідає плоскодонному відбивачу діаметром 1 мм) частоту УЗК необхідно встановлювати в інтервалі 4,2…4,5 МГц, а часову тривалість імпульсу – 6…8 періодів заповнення вказаної частоти. Розроблено метод ультразвукового імерсійного контролю, який включає розміщення контрольного зразка з моделлю дефекту заданого розміру в імерсійній рідині, опромінення одним п’єзоперетворювачем дефекту в зразку ультразвуковим імпульсом, що складається з кількох періодів високої частоти, прийом другим п’єзоперетворювачем імпульсу відбитого дефектом, корегування частоти і тривалості ультразвукового опромінюючого імпульсу до отримання максимальної амплітуди імпульсу, відбитого дефектом, і проведення дефектоскопії з встановленими параметрами опромінюючого імпульсу. Розроблені спеціальний генератор для живлення п’єзоелектричних перетворювачів та смуговий посилювач для прийнятих ультразвукових імпульсів. Розроблено модель акустичного імерсійного блока приладу, суть якої полягає в використанні двох прямих п’єзоперетворювачів, розташованих на відстані один від одного, яка визначається індикатрисою розсіювання дефекту, розмір якого заданий нормативно технічною документацією. Використання розробки дало можливість збільшити амплітуду імпульсу відлуння, відбитого від плоскодонного відбивача діаметром 1 мм, по відношенню до амплітуди завад до 15 дБ. Оцінено ефективність результатів виконаних досліджень в порівнянні з відомими розробками. Результати розробок захищені 2 патентами на корисну модель. The dissertation on obtaining a scientific degree of Ph.D. in specialty 05.11.13 "Devices and methods of control and definition of structure of substances" - National technical university "Kharkiv polytechnic institute". The dissertation is devoted to the development of a new method and means for providing ultrasonic immersion testing with increased sensitivity to the detection of internal defects of minimal size. An analytical review and analysis of modern tools and methods of non-destructive testing and diagnostics of railway axles and their blanks. The influence of various types of noise, technical level of devices and instruments for testing of railway axles, circuit solutions of their power supplies, reception of ultrasonic pulses from products are considered, known advantages, disadvantages and possibilities of their use in research and development are defined. As a result of the information source analysis it is established that ultrasonic contact and immersion methods have their advantages and disadvantages in detecting internal defects and assessing the structure of steel of railway axles and blanks for their manufacture. Technical contradictions for each of them dictate the need to perform research of these methods, followed by their solution. Due to the increasing requirements for the quality of railway axles, the need to increase the sensitivity of ultrasonic flaw detection by calibrating the control device on models of smaller defects, such as flat-bottomed reflector with a diameter of 1 mm or more instead of 3 mm or more [10]. To ensure high sensitivity to the detection of minimal defects, it is necessary to develop methods and means of their implementation. The directions of dissertation research are defined and substantiated. The physical model of product testing in the immersion variant is determined by the results of the analysis of which the minimum thickness of the immersion liquid layer between the combined piezoelectric transducer (PET) and the surface is determined. This thickness must be greater than the spatial duration of the ultrasonic pulse рСt (where р С - the speed of propagation of longitudinal waves in the liquid; t - pulse duration in time). The calculation of the minimum thickness of the layer of immersion fluid between the combined PET and the surface of the workpiece of the railway axis, which must be at least 46 mm with a diameter of the railway axis of 170 mm. A physical-mathematical model of railway axle testing in the immersion variant has been developed. Theoretical calculation of the ultrasonic path for railway axles testing by a longitudinal transducer in the reflection of ultrasonic pulses from models of defects in the form of flat-bottom reflectors of different diameters, taking into account the attenuation of signals in refraction on a curved surface and transformation. An unambiguous relationship between the size of the defect and the frequency of ultrasonic oscillations, which indicates the need to establish a rational value of the frequency of ultrasonic oscillations in identifying the model of the defect specified by regulatory and technical documentation for control. The issue of rational choice of duration of ultrasonic pulses of PET power supply, aimed at increasing the sensitivity of testing, is solved. It is proven that it is possible to significantly raise the sensitivity of testing by increasing the duration of ultrasonic pulses. Such an approach is due to the concentration of signal energy in a narrow range of the spectrum and the wide possibilities of filtering the useful signal from interference. It is advisable to choose the pulse duration of at least 3… 5 periods of signal filling frequency. However, to use pulses of extra duration it is not expedient as at the same time the "dead" (not controlled) zone at a surface of metal increases. It has been theoretically and experimentally proven that the sensitivity of ultrasonic immersion control of railway axles can be increased by feeding piezoelectric transducers with packet current pulses with a given filling frequency and time duration. It is established that to ensure sufficient sensitivity of ultrasonic immersion testing of railway axles (detection of internal defects of an effective size corresponding to a 1 mm diameter flat-bottom reflector), the ultrasonic frequency must be set in the range 4.2… 4.5 MHz with pulse temporal duration of 8 periods of filling of the specified frequency. A method of ultrasonic immersion testing has been developed, which includes immersing a control sample with a model of a defect of a given size into immersion liquid, irradiating a defect in the sample using a singular probe and a singular ultrasonic pulse, which consists of several high-frequency periods, receiving a pulse reflected by the defect with a second probe, adjusting the frequency and duration of the irradiating ultrasonic pulse until obtaining the maximum amplitude of the pulse reflected by the defect, and conducting defectoscopy with the specified parameters of the irradiating pulse. A special generator for powering piezoelectric transducers and a band amplifier for received ultrasonic pulses have been developed. A model of the acoustic immersion unit of the device has been developed, the essence of which is to use two longitudinal PETs located at a certain distance from each other, which is determined by the scattering indicatrix of the defect, the size of which is specified by the normative technical documentation. The use of development made it possible to increase the amplitude of the echo pulse reflected from a 1 mm diameter flat-bottomed reflector, relative to the amplitude of the noise to 15 dB. The efficiency of the results of the performed researches in comparison with the known developments is estimated. The development results are protected by 2 utility model patents.

Signal amplifier is an electronic device that amplifies the signal applied at the input and delivers an amplified signal at the output. When a part of the output signal is taken and mixed with the input signal, the process is called feedback. Feedback may be of two types; positive feedback in which the feedback part of the signal is in-phase with the input signal, and therefore, the overall gain of the amplifier increases. However, if the feedback signal is out of phase, the overall gain decreases and the process is termed as negative feedback. Both positive and negative feedbacks are frequently used; former to convert an amplifier into Oscillator and later to stabilize the amplifier operation. Details of the two types of feedbacks, methods of achieving them, their effect on the performance of two port networks, etc. are discussed in this chapter.

Hybridization chain reaction (HCR) can be divided into two categories: linear HCR and nonlinear HCR. In traditional linear HCR, the relatively slow kinetics and less sufficient sensitivity largely limit its scope of application. In the nonlinear HCR system, under the trigger of the initiator, the judicious designed substrate sequences (hairpin or hairpin-free) will self-assembly to dendritic or branched DNA nanostructures with exponential growth kinetics. Given the advantages of its enzyme-free, high-order growth kinetic, high sensitivity, and simple operation, nonlinear HCR is regarded as a powerful signal amplifier for the detection of biomarkers by integrating with versatile sensing platforms in the past few decades. In this review, we describe the basic features of nonlinear HCR mechanism and classify the nonlinear HCR into several categories based on their self-assembly mechanisms: the branched HCR, dendritic HCR, hydrogel-based clamped HCR, and other types of HCR. Then, we summarize the recent development of nonlinear HCR in biosensing, such as nucleic acid, protein, enzyme activities, and cancer cell detection, etc., and we also review the current applications of nonlinear HCR in bioimaging (mRNA in situ imaging). We choose several representative works to further illustrate the analysis mechanisms via various detection platforms, such as fluorescence, electrochemical, colorimetric, etc. At last, we also review the challenges and further perspectives of nonlinear HCR in the use of bioanalysis.

Telomerase is closely linked to the physiological transformation of tumor cells and is commonly overexpressed in most types of tumor cells. Therefore, telomerase has become a potential biomarker for the process of tumorigenesis, progression, prognosis and metastasis. Thus, it is important to develop a simple, accurate and reliable method for detecting telomerase activity. As a high signal-to-noise ratio mode, electrochemiluminescence (ECL) has been widely applied in the field of biomedical analysis. Here, our objective was to construct an improved ECL signal amplifier for the detection of telomerase activity. Methods: A cascaded ECL signal amplifier was constructed to detect telomerase activity with high selectivity via controllable construction of a lysine-based dendric Ru(bpy)3 2+ polymer (DRP). The sensitivity, specificity and performance index were simultaneously evaluated by standard substance and cell and tissue samples. Results: With this cascaded ECL signal amplifier, high sensitivities of 100, 50, and 100 cells for three tumor cell lines (A549, MCF7 and HepG2 cell lines) were simultaneously achieved, and desirable specificity was also obtained. Furthermore, the excellent performance of this platform was also demonstrated in the detection of telomerase in tumor cells and tissues. Conclusion: This cascaded ECL signal amplifier has the potential to be a technological innovation in the field of telomerase activity detection.

Consideration is given to the research status and prospects for development of plasma relativistic microwave electronics as a basis for plasma masers. Possible applications are determined for plasma masers as high-power sources of microwave pulses. Design features of masers and their radiation characteristics are considered with a view to the type of device: self-oscillator, external signal amplifier, or noise amplifier.

Immunoassays and immunosensors are extensively described diagnostic tools. However, they often entail time-consuming multi-step procedures that are difficult to perform outside centralized diagnostic laboratories, such as at point-of-care settings, where extremely simple assay paths are required. In this work, a commercial polymeric enzyme, polyHRP, has been used as a signal amplifier for detection of matrix metalloproteinase 9 (MMP-9). Contrary to previous reports, signal enhancement has been exploited here to reduce the number and duration of the steps of a classical multistep enzyme-linked immunosorbent assay (ELISA) while retaining its original sensitivity. The two assay formats produced, a simplified ELISA and an electrochemical immunosensor, could be carried out in about 1 h and 45 min, respectively, but detected MMP-9 with linear range, limit of detection (LOD), limit of quantification (LOQ), sensitivity, and variability comparable to the original ELISA that took >5 h, and quantitated successfully MMP-9 in plasma samples and uterine aspirates from patients. These results demonstrate that the implementation of signal amplifiers, such as polyHRP, allows the optimization of simplified immunoassays, maintaining the high performance obtained with longer multi-step paths. Furthermore, the strategy reported is extremely simple and potentially implemented elsewhere by other researchers with minimal technical requirements.

This work deals with the design of a portable device for measuring and monitoring corrosion variables. The measured variables are the electrochemical potential (EP) and electrochemical current (EC). Using these signals the localization index (LI) and the corrosion rate (CR) can be estimated. Since electrochemical potential (EP) and electrochemical current (EC) are weak signals, an electronic circuit was designed and developed for measuring these two variables. The electronic circuit includes a signal amplifier, a physical filter, and an Analog to Digital Converter (ADC). To estimate the IL and CR the statistical method and Neural Network method were used and compared. The device advantages are its low-cost of construction, its portability and the possibility to analyze the corrosion variables in different materials. Experimental tests carried out using 6061-T6 aluminum shown the effectiveness of the proposed device and methods and the versatility of the portable device.

The work offers the improvement of oxygen monitoring instrument of a gas torch with the use of a simple tool base which does not demand a high level of qualification of operator. An electronic block of pyrometer was developed and investigated. The pyrometer is designed to measure flow of solid particles in a high-temperature two-phase flow. The operating range of spectrum is 0,5•10-6 ... 1,1•10-6 m. The justification of choice of radiation receiver was carried out and calculation of electrical signal at radiation receiver was performed. The radiation receiver is a photodiode FD-25K, which is selective, of little inertia, has small dimensions, operates at a small voltage of power source. The spectral range measuring flux of radiation flame is limited by spectral sensitivity of radiation receiver (wavelength 0,5•10-6 ... 1,1•10-6 m). The signal amplifier is designed. The signal amplifier is a converter of an electric current of a photodiode into a voltage. The photodiode is switched on in photovoltaic mode (without bias voltage), which ensures the absence of dark current. The calculation and experimental values of the parameters of the electronic unit of the measuring device are presented in the article.

To effectively detect trace disease markers in whole blood is still a great challenge. Here, a separated capture-detection electrochemical detection platform based on active capture capability/signal amplifier/funnel-type detection device is proposed. Firstly, Mg-based microswimmers modified with magnetic nanomaterials (Mg/ferric oxide/polydopamine/heparin, Mg/Fe3O4/PDA/Hep) are prepared, which can react with water to produce hydrogen as the driving source and Mg2+ as the signal amplifier to cyclically cut the Mg2+-induced nucleic acid fragment. Secondly, the Mg-based microswimmer gradually consumed the Mg microsphere and left the magnetic nanomaterials containing the trapping agent, which can be completely recovered by the magnetic electrode. Finally, the funnel-type electrochemical detection device was applied to fully collect the recognizer for detection in milliliter solution. This strategy can be expected to provide a candidate approach for the early and accurate diagnosis of diseases.

The exploration of electroactive labelling with tailorable and strong differential pulse voltammetry (DPV) responses is of great importance in accurate and sensitive screening of a panel of biomarkers related to cancer. Herein, shell-encoded gold nanoparticles (Au NPs) are fabricated and give rise to shell species-dominated DPV peak potentials. Two independent DPV peaks appear at -0.08V for Au@Cu2O core-shell NPs and 0.26V for Au@Ag core-shell NPs. Shell-encoded Au NPs drastically exhibit shell thickness-tunable amplified peak currents. The non-interfering and amplified DPV responses enable shell-encoded Au NPs to be an alternative electrochemical signal amplifier for dual screening of carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP). The limits of detection (LODs) are calculated to be 1.8pg/mL for CEA and 0.3pg/mL for AFP. In comparison to the parallel single-analyte assays, shell-encoded Au NPs engineered electrochemical aptasensors offer multiplexing capability and show significant prospects in biomedical research and early diagnosis of diseases.

Nanozymes are an excellent class of optical reporters for the development of sensitive biosensors for widespread applications. In this study, mesoporous core-shell palladium@platinum (Pd@Pt) nanoparticles were synthesized and then applied as signal amplifier in a dual lateral flow immunoassay (LFIA) and integrated with a smartphone-based device for use in simultaneous detection of Salmonella Enteritidis and Escherichia coli O157:H7. After optimization, the limit of detections were calculated to be ∼20 cfu/mL for S. Enteritidis and ∼34 cfu/mL for E. coli O157:H7, respectively. The greatly improved sensitivity was contributed by the peroxidase-like catalytic activity of the Pd@Pt nanoparticles for signal enhancement and the parallel design of dual detection for eliminating the cross-interference. The estimated recoveries of the dual LFIA range from 91.44 to 117.00%, which indicated that the developed method is capable of detecting live bacteria in food samples. This approach provides an attractive platform for S. Enteritidis and E. coli O157:H7 detection using a smartphone-based device as the sole piece of equipment, indicating great promise for foodborne pathogen analysis or in-field food safety tracking.

DNA performs diverse functional roles in biology, nanotechnology, and biotechnology, but current methods for autonomously synthesizing arbitrary single-stranded DNA are limited. Here, we introduce the concept of Primer Exchange Reaction (PER) cascades, which grow nascent single-stranded DNA with user-specified sequences following prescribed reaction pathways. PER synthesis happens in a programmable, autonomous, in situ, and environmentally responsive fashion, providing a platform for engineering molecular circuits and devices with a wide range of sensing, monitoring, recording, signal processing, and actuation capabilities. We experimentally demonstrate a nanodevice that transduces the detection of a trigger RNA into the production of a DNAzyme that degrades an independent RNA substrate, a signal amplifier that conditionally synthesizes long fluorescent strands only in the presence of a particular RNA signal, molecular computing circuits that evaluate logic (AND, OR, NOT) combinations of RNA inputs, and a temporal molecular event recorder that records in the PER transcript the order in which distinct RNA inputs are sequentially detected., Graphical Abstract

One of the dangerous technical leakage channels is acoustic information. The paper describes two designed noise generators: analog and digital. Their main researched characteristics: frequency range, noise quality factor. The methodology for calculating the entropy coefficient of noise quality is considered. Designed generators correspond to the considered criteria and can be integrated into the vibroacoustic protection.

Here, a target-induced three-dimensional DNA network structure (T-3D Net) produced by catalytic hairpin assembly (CHA) was proposed as a novel signal amplifier to fabricate an ultrasensitive electrochemiluminescence (ECL) biosensor for microRNAs detection. Usually, conventional CHA can produce only one output DNA in each target cycle, while the proposed strategy could produce multiple output DNA by using DNA-functionalized magnetic beads (MBs) and gold nanoparticles (AuNPs) to form T-3D Net. Then, the T-3D Net with high loading capacity could be completely collapsed by dissolving AuNPs to efficiently convert trace microRNA-21 into a large amount of output DNA. Furthermore, the nanocomposite containing Ru(bpy)

The high-affinity IgE Fc receptor (FcεRI) β chain acts as a signal amplifier through the immunoreceptor tyrosine-based activation motif in its C-terminal intracellular region. Polymorphisms in FcεRI β have been linked to atopy, asthma, and allergies. We investigated the secondary structure, conformation, and thermal stability of FcεRI β polymorphic (β-L172I, β-L174V, and β-E228G) proteins. Polymorphisms did not affect the secondary structure and conformation of FcεRI β. However, we calculated Gibbs free energy of unfolding (ΔGunf) and significant differences were observed in ΔGunf values between the wild-type FcεRI β (β-WT) and β-E228G. These results suggested that β-E228G affected the thermal stability of FcεRI β. The role of β-E228G in biological functions and its involvement in allergic reactions have not yet been elucidated in detail; therefore, differences in the thermal stability of β-E228G may affect the function of FcεRI β.

Biosensors hold prominent role in the detection of various analytes related to bioanalytical applications, i.e., biosensing. One of the strategies used to increase the biosensing capability of a biosensor is by decorating the sensing electrode with advanced material, one of which is bimetallic nanomaterials and its nanocomposites, that greatly enhance the specificity and sensitivity of biosensors. The enhancements provided by this nanomaterial are not only contributed by the inherent properties of the constituent material but also attributable to its finite size and architectural features, and sometimes biomimetic behavior. For those reasons, this review summarized: (1) the basic information of bimetallic nanomaterials and its nanocomposites; (2) the summary of the synthesis and architectures of the bimetallic nanomaterials and its nanocomposites; (3) recent advancements in the bimetallic nanomaterials/composites that contributes to the enhancement of biosensors, where the bimetallic nanomaterials/composites work as either electrode modifier, signal amplifier, or even as recognition material. In addition, the current challenge and insights for future prospective developments of bimetallic nanomaterials and its nanocomposite for biosensing applications are summarized.

Nanomaterials exhibit immense potential for varied applications ranging from environmental monitoring, in vitro and in vivo diagnostics, catalysis, etc. Among various applications, nanomaterial-based biosensors using various transduction modes play a pivotal role particularly due to their capability to act as a signal amplifier. Precise tailoring of their structures in nanoscale can play a central role in biosensing applications. In the light of the information mentioned earlier, bioinspired approaches toward the development of cost effective and high surface-to-volume ratio–based nanostructural materials are expected to be a promising area. Herein, we wish to focus on the synthesis of nature-derived metallic and nonmetallic nanomaterials and surface engineering of the materials with recognition elements, enzymes, antibodies, and aptamers. Furthermore, we desire to discuss various transduction modes that can be used with such nanomaterial-based platforms. Finally, we discuss the future prospects of such nanostructures in the development of translational biosensing platforms.

Exploring innovative technologies to precisely quantify biomolecules is crucial but remains a great challenge for disease diagnosis. Unfortunately, the humoral concentrations of most biotargets generally vary within rather limited scopes between normal and pathological states, while most literature-reported biosensors can detect large spans of targets concentrations, but are less sensitive to small concentration changes, which consequently make them mostly unsatisfactory or even unreliable in distinguishing positives from negatives. Herein, a novel strategy of precisely quantifying the small concentration changes of a certain biotarget by editing the dynamic ranges and sensitivities of a lanthanide-based metal-organic framework (Eu-ZnMOF) biosensor is reported. By elaborately tailoring the biosensor's structure and surface areas, the tunable Eu-ZnMOF is developed with remarkably enhanced response slope within the "optimized useful detection window," enabling it to serve as a powerful signal amplifier (87.2-fold increase) for discriminating the small concentration variation of urinary vanillylmandelic acid (an early pathological signature of pheochromocytoma) within only three times between healthy and diseased subjects. This study provides a facile approach to edit the biosensors' performances through structure engineering, and exhibits promising perspectives for future clinical application in the non-invasive and accurate diagnosis of severe diseases.

The work offers the improvement of oxygen monitoring instrument of a gas torch with the use of a simple tool base which does not demand a high level of qualification of operator. An electronic block of pyrometer was developed and investigated. The pyrometer is designed to measure flow of solid particles in a high-temperature two-phase flow. The operating range of spectrum is 0,5·10-6 ... 1,1·10-6 m.The justification of choice of radiation receiver was carried out and calculation of electrical signal at radiation receiver was performed. The radiation receiver is a photodiode FD-25K, which is selective, of little inertia, has small dimensions, operates at a small voltage of power source. The spectral range measuring flux of radiation flame is limited by spectral sensitivity of radiation receiver (wavelength 0,5·10-6 ... 1,1·10-6 m).The signal amplifier is designed. The signal amplifier is a converter of an electric current of a photodiode into a voltage. The photodiode is switched on in photovoltaic mode (without bias voltage), which ensures the absence of dark current. The calculation and experimental values of the parameters of the electronic unit of the measuring device are presented in the article., Удосконалено вимірювальний прилад контролю витрат кисню газового пальника з використанням нескладної інструментальної бази, яка не вимагає високого рівня кваліфікації оператора. Виконано проектування та дослідження електронного блоку пірометра. Пірометр призначений для вимірювання потоку частинок у високотемпературному двофазному потоці. Робочий діапазон спектра електромагнітних хвиль від 0,5·10-6 до 1,1·10-6 м.Виконано обґрунтування вибору приймача випромінювання та проведено розрахунок електричного сигналу на приймачі випромінювання. Приймачем випромінювання є фотодіод ФД-25K, який є селективним, має невелику інерцію, невеликі розміри, працює при невеликій напрузі джерела живлення. Спектральний діапазон вимірювання потоку випромінювання полум’я обмежено спектральною чутливістю приймача випромінювання (довжина хвилі 0,5·10-6 ... 1,1·10-6 м).Виконано проектування підсилювача сигналу. Підсилювачем сигналу є перетворювач електричного струму фотодіода в напругу. Фотодіод ввімкнено в фотогальванічному режимі (без напруги зсуву), що забезпечує відсутність темнового струму. В дослідженні приведено розрахункові та експериментальні значення параметрів електронного блоку вимірювального приладу.