Rapid Procedure Research Articles

Rapid and eco-friendly microextraction procedure based on green hydrophobic deep eutectic solvent for simultaneous determination of five sex hormones from cosmetic samples

Hormones, which are among the endocrine disruptors, are used in many fields and their use in cosmetic products has recently attracted considerable attention. Despite the negative health consequences, there is no detailed guidance that limits the use of these endocrine disruptors. This study aimed to develop a green hydrophobic deep eutectic solvent (HDES)-based microextraction method for the detection and quantification of sex hormones (progesterone, β-estradiol, estrone, ethinylestradiol, and testosterone) in different cosmetic products. The best value for extraction recovery was obtained by using DL-menthol and dodecanoic acid as green HDES in a 4:1 mole ratio. Optimization parameters such as HDES volume, pH, sample volume, centrifugation time, mixing type, and mixing time were investigated for cosmetic samples to be used as real samples. Furthermore, the extraction recovery values ranged from 85.7 % to 101.3 % and the detection limit was between 2.33–3.30 ng mL−1. Additionally, three different greenness methods, namely ComplexGAPI, AGREEprep, and BAGI, were used to evaluate how green the proposed method is in this study. The microextraction procedure developed in this study was successfully applied to five different cosmetic samples that will be used as real samples to detect and determine sex hormones.

Rapid Single-Step Detection of Polyfluoroalkyl Substances (PFAS) Using Electropolymerized Phenoxazine Dyes.

Per- and polyfluoroalkyl substances (PFAS) are highly stable ubiquitous contaminants that have been recently added to the list of regulated chemicals. While methods for PFAS detection exist, analysis is difficult, involving a tedious protocol and expensive instrumentation. Here, we demonstrate the first implementation of a phenoxazine dye as a sensing probe that facilitates rapid and inexpensive detection of representative PFAS, e.g., perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), at sensitivity levels covering the recently established Environmental Protection Agency (EPA) limits. The method comprises an electrode modified with a stable redox film of Meldola blue (MB) in its electropolymerized form (epMB), which provides amino sites for electrostatic interactions with PFAS. Long-chain PFAS bind specifically to the epMB, inducing a hydrophobic-type cluster formation through ion-pair and F-F interactions. This binding generates concentration-dependent changes in the epMB/epMB+ oxidation, enabling rapid and sensitive quantification in a single step with high sensitivity, reaching a limit of detection of 0.4 ppt for PFOS and 1.65 ppt for PFOA. The sensor demonstrates good selectivity toward common interfering compounds like humic acid, sodium chloride and fluoride, metallic ions (Cu, Hg, As), as well as pesticides. In addition to PFOS and PFOA, the sensors can measure other perfluoroalkyl compounds, demonstrating potential as a tool for rapid quantification of a total PFAS index, with affinity for long-chain PFAS. This work highlights the integration of redox receptors into an electrochemical sensor to solve the grand challenge of PFAS analysis using a rapid and inexpensive procedure, with potential for field deployment.

Using Transparent Cap of Endoloop in Emergency Hemostasis as a Novel Rapid Clot Removal Procedure for Acute Upper Gastrointestinal Hemorrhage.

Using Transparent Cap of Endoloop in Emergency Hemostasis as a Novel Rapid Clot Removal Procedure for Acute Upper Gastrointestinal Hemorrhage.

Enhancement of loop-mediated isothermal amplification (LAMP) with guanidine hydrochloride for the detection of Streptococcus equi subspecies equi (Strangles).

Streptococcus equi subspecies equi, commonly referred to as "strangles", poses a significant biosecurity challenge across equine farms worldwide. The continuous prevalence and highly transmissibility of strangles necessitates a rapid and accurate diagnostic procedure. However, current "gold-standard" techniques, such as cultures and quantitative polymerase chain reaction (qPCR), are unreliable or inaccessible, and require lengthy periods between sample collection and results. Moreover, the lack of a standardized detection protocol can lead to variations in results. This study aimed to develop a reproducible and field-deployable diagnostic assay to detect strangles in real-time. Utilising the rapid technique loop-mediated isothermal amplification (LAMP), we developed an assay targeting a conserved region of the S. equi-specific M gene (SeM). Additionally, we optimised our assay with guanidine hydrochloride (GuHCl) to enhance the assay's performance and detection capabilities. The Str-LAMP was able to detect S. equi within 13 minutes and 20 seconds for both synthetic DNA and clinical isolates, with a limit of detection (LOD) of 53 copies/µl. Our assay demonstrated high repeatability with the inter-coefficient of variation ranging from 0.17% to 3.93%. Furthermore, the clinical sensitivity and specificity was calculated at 91.3% and 93.3%, respectively, with a correct classification rate of 91.8%. The implementation of this newly developed strangles assay can be employed as an efficient aid for in-field surveillance programs. The assay's reproducibility can allow for equine managers to undertake routine self-surveillance on their properties, without the requirement of specialised training. The Str-LAMP assay has the potential to be a valuable tool to help mitigate potential strangles outbreaks.

Posture-dependent modulation of marmoset cortical motor maps detected via rapid multichannel epidural stimulation

Recent neuroimaging and electrophysiological studies have suggested substantial short-term plasticity in the topographic maps of the primary motor cortex (M1). However, previous methods lack the temporal resolution to detect rapid modulation of these maps, particularly in naturalistic conditions. To address this limitation, we previously developed a rapid stimulation mapping procedure with implanted cortical surface electrodes. In this study, employing our previously established procedure, we examined rapid topographical changes in forelimb M1 motor maps in three awake male marmoset monkeys. The results revealed that although the hotspot (the location in M1 that elicited a forelimb muscle twitch with the lowest stimulus intensity) remained constant across postures, the stimulus intensity required to elicit the forelimb muscle twitch in the perihotspot region and the size of motor representations were posture-dependent. Hindlimb posture was particularly effective in inducing these modulations. The angle of the body axis relative to the gravitational vertical line did not alter the motor maps. These results provide a proof of concept that a rapid stimulation mapping system with chronically implanted cortical electrodes can capture the dynamic regulation of forelimb motor maps in natural conditions. Moreover, they suggest that posture is a crucial variable to be controlled in future studies of motor control and cortical plasticity. Further exploration is warranted into the neural mechanisms regulating forelimb muscle representations in M1 by the hindlimb sensorimotor state.

A-232 Characterize and reduce positive interference of hemolysis on Fungitell testing for (1, 3)-β-glucan (BDG) in serum

Abstract Background Fungitell is an FDA cleared in vitro diagnostic product with an indication for use as an adjunct test for the diagnosis of invasive fungal infection. This assay has been established using a kinetic photometric method. A key aspect of this (1→3)-β-glucan (BDG) activated cascade reaction is its characteristic kinetic optical density profile. Interference which affects the BDG kinetic profile makes data analysis and interpretation difficult. This interference is roughly classified as being associated with hemolysis, icterus, lipemia (collectively HIL), and other non-specific factors. Methods In this study, we found that the use of 5% PEG-8000 supplemented serum (1:1 ratio of the volume of serum to 10% PEG-8000 solution with 0.1 M Tris-Cl, pH 7.4), heated at 80°C for 3.5 min, followed by centrifugation at 15,000 x g for 10 minutes (PEG-X Method) can largely eliminate the hemolysis-associated interference. Results The treated serum Fungitell BDG reaction curves are more like the ideal BDG kinetic profile. The recovery of introduced β-glucan has been shown to be acceptable (80-120%) for hemolyzed specimens. Conclusions This simple and rapid procedure shows promise as a pre-analytical treatment to reduce serum interference in the Fungitell β-glucan test for a substantial fraction of samples that produce currently unreportable results.

Assessment of reduction in stimulus generalization of ethanol-seeking during recovery: A rapid procedure

Previously, we developed a procedure which showed that longer histories of reinforced alternative behavior decrease the risk of relapse caused by a range of stimuli which had previously occasioned drinking. The decrease in relapse risk was likely due to a decrease in attention to the stimuli over the course of repeated engagement in the alternative behavior. However, this previous procedure was time consuming and did not mirror the procedure we used to observe changes in relapse risk. This study aimed at replicating the previous relationship between the duration of engaging in an alternative behavior and shift in stimulus generalization for drinking using a procedure that allows longitudinal analysis over time and is consistent with other procedures we have developed. Rats were trained to respond for ethanol in the presence of one stimulus (16 kHz tone; food Fixed Ratio (FR)150 and ethanol FR5), and for food in the under another stimulus (8 kHz tone; food and ethanol FR5). Then, recovery-like sessions with food predominant responding occurred in the presence of only the low-cost food stimulus. During these sessions, rats were exposed to non-reinforced graded stimuli alternation from 8 to 16 kHz alternating with the reinforced low-cost food stimulus. The number of responses on each (food and ethanol) lever before completing 5 responses on either lever was the main measure. Consistent with the earlier procedure, the current procedure showed that graded variation of tone from 8 to 16 kHz produced a graded increase in responding for ethanol compared to responding for food. In addition, longer periods of engaging in recovery-like responding shift the generalization function downwards. This procedure confirms the earlier pattern of stimulus generalization over longer periods of behavior consistent with recovery. This strengthens our hypothesis that shifts in attention to alcohol-related stimuli are important to the development of relapse resistance during recovery.

Microwave-assisted synthesis of γ-alooh nanoflowers as an adsorbent for cadmium removal from domestic wastewater.

In this study, cadmium ions were effectively removed from domestic wastewaters using an adsorptive treatment strategy based on γ-AlOOH nanoflowers. A novel, rapid, and simple procedure was developed for the synthesis of the nanoflowers. Characterization studies were performed using X-ray powder diffraction patterns and scanning electron microscope images. The synthesized nanoflowers were utilized as adsorbent in the batch adsorption experiments. The influential parameters of the adsorption process were optimized, and a flame atomic absorption spectrophotometry (FAAS) system was used to determine maximum percent removal of cadmium ions. Matrix-matched calibration strategy, in which the calibration plot was developed in wastewater medium, was utilized for the accurate and precise quantification of cadmium in the effluent samples. The percentage removal efficiency values were calculated between 84 and 98% for different concentrations of cadmium ions in the wastewater samples. Equilibrium data was fitted to the four different linearization methods of the Langmuir isotherm model, as well as the Freundlich isotherm model and Elovich isotherm model. The best fitting was achieved for the Langmuir model with a high R2 value of 0.9956 and maximum adsorption capacity was calculated as 6.23mg/g.

Role of tympanocentesis in the prevention of middle ear barotrauma induced by fast buoyant ascent escape from 200 m underwater.

We aimed to study middle ear barotrauma caused by fast compression followed by buoyant ascent escape from 200 m underwater and its effect on the auditory system, and to validate the preventive effect of tympanocentesis on middle ear barotrauma. Twenty Sprague Dawley rats were divided into two groups: rats in group A underwent a simulated fast buoyant ascent escape from a depth of 200 m, while those in group B underwent tympanocentesis before the procedure described for group A. Ear endoscopy, acoustic conductance, and auditory brainstem response (ABR) tests were conducted before and after the procedure to evaluate the severity of middle ear barotrauma and auditory function in both groups. Additionally, histopathological examination of the middle ear in both groups was conducted to evaluate the severity of middle ear barotrauma by observing submucosal haemorrhage. None of the ears in either group showed any abnormalities before the experiment. In group A, middle ear barotrauma was universally observed after the simulation procedure. The tympanograms of all ears were initially type A and became type B after the procedure. Further, after the simulation, the hearing thresholds at different frequencies (4, 8, 16, 24, and 32 kHz) assessed by ABR significantly increased compared to those before the procedure. In group B, no middle ear barotrauma was observed, and the hearing threshold at each frequency did not change significantly compared with post-puncturing. After dissecting the middle ear, gross pathological observations were consistent with the above results. Microscopically, blood accumulation and submucosal haemorrhage in the middle ear cavity were observed in group A but not in group B. Fast buoyant ascent from 200 m underwater can cause middle ear barotrauma, resulting in hearing loss. Tympanic membrane puncture can effectively prevent middle ear barotrauma caused by the rapid buoyant ascent escape procedure.

Potential of near-infrared spectroscopy (NIRS) for prediction of acrylamide formation in French fries in the potato breeding process

Breeding goals of potatoes for deep-frying purposes include high starch contents, good suitability for long-term storage, and low tendency to form reducing sugars as acrylamide precursors. Due to the extensive number of samples, an accurate analysis of acrylamide in French fries and its precursors in tubers is difficult to implement in the breeding process. Therefore, this study aimed to evaluate the suitability of NIRS measurements after minimal sample processing for the prediction of reducing sugar contents in the tubers or acrylamide contents in French fries. An external validation with more than 650 samples consisting of 194 potato genotypes resulted in a prediction accuracy of 51 % for acrylamide and 76 % for reducing sugar content. RPD values of less than 1.5 for acrylamide and between 1.64 and 2.23 for reducing sugar prediction rendered low medium to medium model quality. Nevertheless, acrylamide prediction models based on NIRS measurement of mashed tubers categorised over 80 % of unknown samples correctly as being below or above the European threshold value, indicating suitability as rapid test procedure in the breeding process.

Multi-class plant hormone HILIC-MS/MS analysis coupled with high-throughput phenotyping to investigate plant-environment interactions.

Plant hormones are chemical signals governing almost every aspect of a plant's life cycle and responses to environmental cues. They are enmeshed within complex signaling networks that can only be deciphered by using broad-scale analytical methods to capture information about several plant hormone classes simultaneously. Methods used for this purpose are all based on reversed-phase (RP) liquid chromatography and mass spectrometric detection. Hydrophilic interaction chromatography (HILIC) is an alternative chromatographic method that performs well in analyses of biological samples. We therefore developed and validated a HILIC method for broad-scale plant hormone analysis including a rapid sample preparation procedure; moreover, derivatization or fractionation is not required. The method enables plant hormone screening focused on polar and moderately polar analytes including cytokinins, auxins, jasmonates, abscisic acid and its metabolites, salicylates, indoleamines (melatonin), and 1-aminocyclopropane-1-carboxylic acid (ACC), for a total of 45 analytes. Importantly, the major pitfalls of ACC analysis have been addressed. Furthermore, HILIC provides orthogonal selectivity to conventional RP methods and displays greater sensitivity, resulting in lower limits of quantification. However, it is less robust, so procedures to increase its reproducibility were established. The method's potential is demonstrated in a case study by employing an approach combining hormonal analysis with phenomics to examine responses of three Arabidopsis ecotypes toward three abiotic stress treatments: salinity, low nutrient availability, and their combination. The case study showcases the value of the simultaneous determination of several plant hormone classes coupled with phenomics data when unraveling processes involving complex cross-talk under diverse plant-environment interactions.

Hybrid Cooperative Control of Functional Electrical Stimulation and Robot Assistance for Upper Extremity Rehabilitation.

Hybrid systems that integrate Functional Electrical Stimulation (FES) and robotic assistance have been proposed in neurorehabilitation to enhance therapeutic benefits. This study focuses on designing a cooperative controller capable of distributing the required torque for movement between robotic actuation and FES, thereby eliminating the need for time-consuming calibration procedures. The control schema comprises three main blocks: a motion generation block that defines the desired trajectory, a motor control block including both a weight compensation feedforward and a feedback impedance controller, and an FES control block, based on trial-by-trial Iterative Learning Control (ILC), that adjusts the stimulation intensity according to a predefined stimulation waveform. The feedforward motor assistance can be dynamically regulated using an allocation factor. Experiments involving 12 healthy volunteers were conducted using a one-degree-of-freedom elbow testbed. The experimental results showcased the successful integration of Functional Electrical Stimulation (FES) with robotic actuation, ensuring precise trajectory tracking with a Root Mean Square Error (RMSE) below 7°. Notably, allocating more torque to FES led to a 51 % reduction in motor torque. In conditions where FES operated alone, there was poorer tracking performance with an RMSE of 24° and an early onset of muscle fatigue, as evidenced by a reduced number of achieved repetitions. Furthermore, the hybrid approach enabled 100 fatigue-free elbow flexion repetitions, underscoring the effectiveness of cooperative FES-motor control in extending the benefits of FES-induced exercises. This study proposes a flexible approach which can be extended to a multi-degree-of-freedom hybrid system. Furthermore, it underscores the significance of employing a straightforward and adaptable methodology with a rapid calibration procedure, making it easily transferable to clinical applications.

Current and Future Pharmacopoeial Requirements for the Quality of Extemporaneous Medicinal Products: A Review of Regulatory Standards

INTRODUCTION. The organisation of extemporaneous compounding in pharmacies is currently considered to be a priority for the national healthcare system. Extemporaneous medicinal products used by patients should meet high quality, safety, and efficacy standards. Provision of consistent and science-based requirements for the quality of medicines, particularly those compounded in pharmacies, is a key area of concern for standardisation.AIM. This study aimed to analyse international experience and determine areas for the improvement of standardisation approaches of the State Pharmacopoeia of the Russian Federation to the quality of medicinal products compounded in pharmacies.DISCUSSION. The study investigated the common and distinctive properties of extemporaneous preparations compounded in pharmacies (and not subject to registration) and medicinal products manufactured by pharmaceutical companies. The authors analysed the requirements and recommendations for compounding and quality assurance of extemporaneous medicinal products provided by the regulatory and pharmacopoeial authorities of the Russian Federation, the Republic of Belarus, the European Union, the United Kingdom, the USA, and Canada. The United States Pharmacopeia includes circa 150 individual monographs for non-sterile compounded drug products with particular compositions and over 20 individual monographs for sterile compounded drug products. The European Pharmacopoeia requires that extemporaneous preparation should be organised within the quality assurance framework of a pharmacy after a proper risk assessment. In the Republic of Belarus, extemporaneous medicinal products are compounded in line with the requirements of the Good Compounding Practices and the State Pharmacopoeia of the Republic of Belarus, which provide rapid testing procedures for extemporaneous medicinal products.CONCLUSIONS. The study identified the following areas for the development of requirements for the quality of medicinal products compounded in pharmacies: the determination of rapid testing approaches; the development of pharmacopoeial monographs for active pharmaceutical substances used in extemporaneous compounding, with the Identification section supplemented with an additional subsection on pharmacy-specific analytical procedures; and the development of pharmacopoeial monographs for frequently used compounding formulae.

Construction of Functionalized Oxindoles by Quinone-Carbonate Synergistically Triggered Intermolecular Radical Coupling.

We disclose a rapid and nontoxic procedure to construct various oxindoles. This method harnesses the power of a catalytic amount of quinone in synergy with Cs2CO3, showcasing remarkable compatibility with a wide range of functional groups. Mechanistic investigations reveal that it operates via a radical pathway, likely initiated by the single-electron transfer from quinone-Cs2CO3 complexes. This pivotal electron transfer event leads to the generation of a crucial alkyl radical intermediate, contributing to the overall success and efficacy of the transformation.

Influence of the annealing schemes on the formation and stability of Ni(Pt)Si thin films: Partial, laser, total, and one-step annealings

In this study, the impact of various annealing schemes on the formation and agglomeration mechanisms of ultrathin Ni(Pt)Si films is investigated. To this end, 11 ± 1 nm-thick Ni(Pt)Si films are grown on 300 mm Si(100) wafers using various traditional rapid thermal annealing procedures as well as laser annealing. The obtained silicide films are then subjected to additional annealing between 500 and 800 °C, to evaluate their stability at high temperature. The correlation between the as-grown Ni(Pt)Si film properties and their capability to withstand agglomeration is analyzed via a complementary approach of several techniques (Rs, ellipsometry, TEM-EDX, SEM, and EBSD). Texture comparison for ultrathin films give deeper insights into the role of the NiSi-(010) and NiSi-(013) orientations in the agglomeration phenomenon. Depending on the annealing schemes used during the silicide formation, there is a strong correlation between the initial microstructure of Ni(Pt)Si films and their subsequent degradation. Indeed, cross-analysis of these different key parameters indicates that the presence of small Ni(Pt)Si grains (40 nm) obtained after laser annealing, and a high ratio of Ni(Pt)Si grains oriented along the (013) direction appears to be more efficient in delaying the agglomeration to higher temperatures.

Simple and Ultrasensitive Nanozyme-Linked Immunosorbent Assay for SARS-CoV-2 Detection on a Syringe-Driven Filtration Device.

This work proposed a simple and ultrasensitive nanozyme-based immunoassay on a filtration device for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (NP). Gold core porous platinum shell nanoparticles (Au@Pt NPs) were synthesized with high catalytic activity to oxidize 3,3',5,5'-tetramethylbenzidine, leading to an oblivious color change. The filtration device was designed based on the size difference of magnetic beads, filter membrane pore, and Au@Pt NPs. A simple, rapid, and consistent washing procedure can be performed with the help of a plastic syringe. This detection method could realize the quantitative detection of SARS-CoV-2 NP within 80 min for point-of-care needs. The limit of detection for the SARS-CoV-2 antigen was 0.01 ng/mL in buffer. The coefficients of variation of the assay were 1.78% for 10 ng/mL SARS-CoV-2 antigen, 2.03% for 1 ng/mL SARS-CoV-2 antigen, and 2.34% for the negative sample, respectively. The specificity of the detection platform was verified by the detection of various respiratory viruses. This simple and effective detection system was expected to promote substantial progress in the development and application of virus immunodetection technology.

Engagement in rapid public health research among young people from underserved communities: maximising opportunities and overcoming barriers

BackgroundInclusion in public health research of young people from low-income households and those from minority ethnic groups remains low. It is recognised that there is a need to change the way in which research is conducted so that it becomes more inclusive. The aim of this work was to identify novel and innovative ways to maximise recruitment and inclusion of diverse participants when doing co-production within very short time frames for emergency responses.MethodWe conducted interviews with young people from low-income and minority ethnic backgrounds, and members or leaders of groups or organisations supporting or representing young people from underserved communities.ResultsA total of 42 participants took part in an interview. This included 30 young people from low income or minority ethnic backgrounds and 12 community leaders/service providers. Of the 30 young people, 26 participants identified as female and 12 participants identified as being from a minority ethnic background. Participants discussed a number of interrelated barriers to research involvement and identified ways in which barriers may be reduced. Prejudice and discrimination experienced by young people from underserved communities has led to substantial mistrust of educational and governmental establishments. Rigid and unfamiliar research practices further limit the involvement of young people. Four themes were identified as ways of supporting involvement, including: making opportunities available for young people, adaptations to research governance, understanding and acknowledging challenges faced by young people, and ensuring reciprocal benefits.ConclusionThis research explored barriers to engagement in rapid public health co-production. Working with communities to co-produce rapid recruitment and research procedures to suit the needs and the context in which young people live is necessary.

Determination of hydroquinone in beverages using colorimetric and electrochemical sensors on paper-based device.

Hydroquinone (HQ) is aphenolic compound used in industry processes. We aim to demonstrate a rapid and simple procedure forthe determination ofHQ. This work has developed two techniques, including colorimetric and electrochemical sensors on paper-based devices. Firstly, we havedevelopedthe colorimetric detection for the rapid screening test of HQ using 1.5% 4-(dimethylamino) benzaldehyde with alkaline condition (5M NaOH). Under suitable conditions, the calibration curve between the intensity and HQ concentration wasin the range of50-500mg L-1. Then, we developed a multi-walled carbon nanotube/graphene oxide/copper/palladium/platinum (MWCNT/GO/Cu/Pd/Pt) onto a screen-printed carbon electrode (SPCE). The optimalamount ofMWCNT/GO/Cu/Pd/Pt nanomaterial is 2mg for HQ detection.The linear concentration range was foundin the range 1 to 20mg L-1anda detection limit was foundto be 0.40mg L-1 (3.6µM) for HQ. Moreover, the proposed device can be applied to determine HQ inrealsamples and is inexpensivetechnique, portable, and low consumer time.

Advocating for a "shift-to-left" in transplant oncology: left grafts, RAPID and dual graft.

The extension of liver transplantation to new oncologic indications might exacerbate the shortage of grafts. Living donor liver transplantation (LDLT) may emerge as a viable resource, although its diffusion in the Western world is still very limited. Several groups have advocated for minimizing the impact on donors by reducing the extent of donor hepatectomy, i.e., shifting from right-lobe to left-lobe or left-lateral segment donation ("shift-to-left"). This is particularly relevant when dealing with non-established indications and could make it more acceptable both for potential donors and for the recipients. Left grafts can be transplanted straightforward, despite a higher risk of small-for-size syndrome, or they can be used in the setting of dual-graft LDLT or RAPID procedures, despite technical complexity. This review will expose the most relevant features of each technique, highlighting their strengths and pitfalls and focusing on outcomes. This wide set of tools should be available at high-volume transplant centers, to propose the best technique to adapt to donor-recipient matching.

Rapid Detection of Methicillin Resistant Staphylococcus Aureus (MRSA) Using Electric-Double-Layer (EDL) Field-Effect Transistor (FET) Biosensors

According to the latest statistics and analysis by American researchers based on the data from 195 countries worldwide, it has been found that one person in every five people died due to sepsis. The annual death caused by sepsis reaches up to eleven million people, and the number of deaths from sepsis is even higher than those from cancer. We believe that the detection of MRSA is necessary.Staphylococcus aureus is the most common pathogen of sepsis. Methicillin-resistant Staphylococcus aureus (MRSA) or Multiple-resistant Staphylococcus aureus is a distinct strain of Staphylococcus aureus. It has mecA gene which codes for penicillin binding protein 2a (PBP 2A) that will remain active under beta lactams antibiotics. This gives bacterial the ability to grow under concentrations of beta-lactam antibiotics which leads to MRSA's resistance to almost all the different penicillin-type antibiotics including methicillin and other beta-lactamase-resistant penicillins.To detect MRSA in the shortest possible time, we adopt field-effect transistor (FET) biosensor for the real-time detection of binding reactions between DNA probe and cDNA. We select DNA probe sequence of mecA to be the aptamer and immobilize probe DNA which are complementary to the target cDNA on the sensor. This process allows DNA strands to attach to the gold surface. After that, we detect the binding reaction of DNA probe and cDNA by analyzing electrical response of field-effect transistor (FET). We can observe that the Id current changes after cDNA hybridizes with DNA probe.In conclusion, in our research results, Field-effect transistor (FET) biosensor can detect concentration ranging from 1fM to 1pM. In addition, we can achieve other advantages such as more portable, higher sensitivity, real-time monitoring capability, and lower detection limits. With this rapid detection procedure, we can do early diagnosis and treatment, thus improving the quality of human life. Keywords: FET, EDL, Aptamer, DNA, MRSA Figure 1