A Binning Approach to Quickest Change Detection with Unknown Post-Change Distribution

The problem of quickest detection of a change in distribution is considered under the assumption that the pre-change distribution is known, and the post-change distribution is only known to belong to a family of distributions distinguishable from a discretized version of the pre-change distribution. A sequential change detection procedure is proposed that partitions the sample space into a finite number of bins, and monitors the number of samples falling into each of these bins to detect the change. A test statistic that approximates the generalized likelihood ratio test is developed. It is shown that the proposed test statistic can be efficiently computed using a recursive update scheme, and a procedure for choosing the number of bins in the scheme is provided. Various asymptotic properties of the test statistic are derived to offer insights into its performance trade-off between average detection delay and average run length to a false alarm. Testing on synthetic and real data demonstrates that our approach is comparable or better in performance to existing non-parametric change detection methods.Comment: Double-column 13-page version sent to IEEE. Transaction on Signal Processing. Supplementary material include

Finding the needle in the haystack: Comparison of methods for salmon louse enumeration in plankton samples

The economic and social implications of salmon louse (Lepeophtheirus salmonis) epidemics in salmon aquaculture drive focus of the dispersal dynamics of the planktonic larval stages. The vast spatial scale and high connectivity of the marine environment creates difficult conditions to monitor the infective planktonic louse stage, whereby the number of samples required for a representative description is bottlenecked by processing capacity. This study assessed five quantification methods for accuracy and precision in enumeration of lice in plankton samples, validated against the benchmark method of light microscopy. Visual-based (fluorescence microscopy and automated fluid imaging) and molecular-based (droplet digital PCR, quantitative fraction PCR and quantitative PCR) were tested using high- and low-density plankton samples spiked with louse copepodids, with spike numbers blind to assessors. We propose an approach to comparative assessment that uses the collective bias and deviation of a test method to determine whether it is acceptably similar to the benchmark method. Under this framework, no methods passed the comparative test, with only ddPCR comparable to light microscopy (87% mean accuracy and 74% precision). qfPCR and fluorescence microscopy were moderately efficient (88% and 67% accuracy, and 36% and 52% precision respectively). Molecular techniques are currently restricted in distinguishing between larval stages, which is an essential distinction for some research questions, but can be economical in processing numerous samples. Overall method suitability will depend on the research objectives and resources available. These results provide evidence for operational accuracy for the tested methods and highlight the direction for further development to optimize their use

Plant-expressed diagnostic proteins and their use for the identification and differentiation of infected and vaccinated animals with foot-and-mouth disease virus

The Foot-and-mouth disease virus (FMDV) affects cloven-hoofed animals and is endemic in most parts of Africa, South America and southern Asia. South Africa is considered a FMDV-free zone but the virus is maintained within the wildlife in the Kruger National Park (KNP), making mitigation of outbreaks a high priority. Diagnostic methods are usually costly due to the high production cost of the reagents used, meaning that regular monitoring and diagnosis of animals around the KNP for FMDV is expensive due to the large amounts of serum continuously being tested. I propose an alternative plant expression platform for the local production of more cost effective diagnostic reagents capable of distinguishing between infected and vaccinated animals (DIVA). I selected the non-structural 3ABC polyprotein of FMDV to express, as it is a suitable candidate as a coating antigen in a competitive enzyme linked immunosorbent assay (C-ELISA) for the detection of neutralizing antibodies in livestock sera. I also chose other variations of the full polyprotein (3AB, 3AB1 and 3B) for expression as they have previously been shown to be effective in FMDV diagnosis. I also selected a second reagent to be expressed: this was the CRAb-FM27 single chain variable fragment (scFv), which binds a 3B epitope on the 3ABC polyprotein and has previously shown to be effective as a competing antibody in a C-ELISA. The 3B antigen and the scFv were successfully expressed and purified from N. benthamiana, which to my knowledge is the first time either has been shown. The plant produced scFv successfully bound the 3B antigen in an I-ELISA. Separately, the plant produced 3B antigen could be used to successfully differentiate FMDV infected and vaccinated guinea pig serum in an I-ELISA. However, testing of these reagents in tandem within a C-ELISA to DIVA sera was inconclusive, and further research is required to optimise C-ELISA conditions

Separation and Identification of Bioactive Compounds from Oplopanax horridus

For centuries, natural products, such as plants, have been used for the prevention and treatment of diseases and ailments. Modern science is now working to identify the beneficial compounds from these sources to implement into pharmaceutical drugs, vitamins or supplements in an area of study called nutraceuticals. The plant Oplopanax horridus, or Devil\u27s Club is a member of the ginseng family and has over 30 documented uses for spiritual and medicinal purposes. The few studies that have been carried out on this plant are limited to the volatile chemicals present. Few studies have determined the plant possesses antifungal, antioxidant and antimicrobial properties but without confirmation of the chemical compounds responsible for these properties. The purpose of this study was to fractionate compounds from a crude sample of Oplopanax horridus by solid phase extraction (SPE) with the assistance of high pressure liquid chromatography (HPLC). These fractions were subjected to antioxidant testing where bioactivity guided further fractionation and analysis by mass spectrometry (MS). The data collected from the mass spectrophotometer was used to propose the chemical compounds present in the antioxidant active samples. Successful separation of natural products was completed by Soxhlet extraction, liquid-liquid extraction, SPE, and HPLC. Three sample sub-fractions were found to be bioactive after the assessment of antioxidant activity with two variations of assays. Mass spectrum data produced ion chromatograms that were useful in the prediction of chemical structures

The effects of early handling on dairy calves' physiological and behavioural responses to routine husbandry procedures

The quality and quantity of human-animal interactions are crucial to animal welfare, productivity and management of livestock on-farm. Forty Holstein Friesian calves, from one week of age, were exposed to experimental handling for five minutes twice daily for five weeks. Calves were allocated to either positive or negative handling treatments (n=20 per treatment). Positive handling required handlers to slowly approach calves whilst using soft voices to encourage voluntary friendly interactions such as gentle pats. Negative handling consisted of continuous 45 second cycles of direct and indirect handling to discourage friendly interactions. Direct handling required handlers to use fast movements and harsh voices whilst forcibly moving animals around the pen. Indirect handling required handlers to stand in the pen, stare at the animals and tap a polyurethane pipe to make noise to maintain disturbance. Two other novel objects, a plastic bag and an empty water bottle filled with stones, were alternatively used each week to prevent habituation to the negative stimulus. At six weeks of age, all animals were subjected to three routine management procedures: restraint, ear tagging and disbudding, which occurred in stated order over a week period. There were no significant treatment differences between positive and negative groups for heart rate or heart rate variability (measured using Polar heart rate watches), eye temperature (measured using infrared thermography), respiration rates (measured visually), struggling behaviour, and plasma cortisol levels (measured during disbudding only). There were however within treatment differences in response to ear tagging, with an increase in heart rate (p less than 0.01) post-ear tagging, and in response to disbudding with an increase in heart rate (p less than 0.001), tail flicking(p less than 0.001) and cortisol levels (p less than 0.001). It was concluded that, under the conditions of this experiment, early handling does not affect the behavioural and physiological responses of calves to routine management procedures. In a follow up trial at three months of age, the initial 40 animals and 20 additional three month old minimally handled animals (controls) were assessed for ease of handling using a force test, which ranked the time and effort required to move animals individually into a crush, and an exit speed test which recorded the animals speed exiting the crush, after two minutes of restraint. There were no significant differences between positive, negative and minimally handled treatment groups for heart rate, respiration rates or behaviour in the crush. However, the minimally handled group did appear to be more fearful of humans, with a significantly quicker entry time (p less than 0.05) into the crush than positive and negative treatment groups. There were no differences in entry scores for effort required to move the animals during the force test or for exit speeds. It was concluded that, under the conditions of the present experiment, initial early handling does not appear to cause long lasting effects on calves' behavioural and physiological responses to routine farm management procedures, but minimal contact with humans early in life may lead to a fear of humans later in life

Identification and Quantification of Black Carbon Particulates in Urban River Sediments Involving a Multi-tiered Analytical Approach

Black Carbon (‘BC’) is routinely defined as the residual carbon fraction resulting from the incomplete combustion of biomass and/or biofuels (Agarwal et al. 2011). BC is best described as spectrum of carbonaceous combustion by-products, encompassing partially combusted, charred plant tissues, to highly graphitized soot (Shrestha et al. 2010). The highly condensed aromatic structures which exist in the BC matrix are largely responsible for its resistance to further biological or chemical degradation, as well as, its efficient sorption properties in soils and sediments (Forbes et al., 2006; Shrestha et al., 2010). Using a multi-tiered geochemical approach, quantification of BC was coupled with environmental forensics of other contaminants of concern in a highly urbanized/industrialized, tidally influenced river (Lower Hackensack River, New Jersey, USA). This approach allowed for further understanding involving the accumulation and mobility of BC particles in relation to other contaminants of concern and the sedimentation fluxes and hydrodynamic processes which influence them. Review of BC as a potential index parameter for other hydrophobic organic compounds, such as the ever-persistent polycyclic aromatic hydrocarbons (PAHs), was included as part of this research due to their synchronous co-emission inputs and complimentary high sorption capabilities. Analytical quantitative efforts included an array of chemical, thermal and oxidative isolation/extraction techniques including: the Lloyd Kahn method for total organic carbon (TOC) analysis, modified TOC analysis for BC determination, EPA Method 8270 for priority PAHs, loss on ignition (LOI), pyrolysis-gas chromatography mass spectrometry (Py-GC/MS) for evaluation of parent and alkylated PAH assemblages, chemothermal oxidation at 375oC (CTO-375), and major and minor elemental analysis involving scanning electron microscopy (SEM). PAH ratios of various principal masses (m/z 178, 202, 228, etc.,) were also utilized in conjunction with alkyl PAH series ratios to infer potential BC source inputs and to allow for a comprehensive analysis of the chemical characteristics of the historically impacted Lower Hackensack River sediment. Lastly, routine ecological and risk assessment analytical techniques, such as grain size distribution and percent moisture (of sediments) were included as part of this comprehensive sediment study. Historical river-sediment data provided by several federal and state agencies were also evaluated to allow for elucidation of spatial trends relative to heavy metal concentrations, PAHs and other contaminants of concern. Ultimately, the results indicate relatively low concentrations of BC (in comparison to TOC) throughout the lower river sediments, with a general increasing trend observed further downstream adjacent to various petroleum related industries. Qualitative and quantitative analysis of BC particles via SEM further revealed the likely presence of coal fly ash, and various amorphous pyrolytic BC particles. The results of this study also demonstrate the importance of considering different analytical approaches when attempting to quantify BC stocks in an urbanized waterway such as the Lower Hackensack River

Construction of an immunosensor for human cytomegalovirus infection diagnosis

Human Cytomegalovirus (HCMV) is a herpes virus that establish a lifelong latent infection of the host, so once a person is infected, the virus persists in a state of cellular latency. Following primary infection, HCMV is excreted in body fluids and its transmission occurs through mucous contact and exposure to urine, blood transfusion and organ or bone marrow transplant procedures, being extremely difficult to identify the transmission route. HCMV infection induces no overt disease in healthy carriers, owing to effective immune control, but this infection can be severe or even fatal in immunosuppressed individuals, fetuses and newborns. Furthermore, HCMV is also relatively common among women in reproductive age, with seroprevalence ranging from 45 to 100%. The diagnosis of HCMV disease remains controversial because of the difficulty of separating patients who are asymptomatic but shedding HCMV in body fluids, from patients who have the symptomatic disease. Nowadays the most common methods for diagnosis of HCMV infection are: - serological tests based on IgM and IgG detection; - direct free HCMV detection by viral isolation and viral antigens detection in tissue, urine or saliva samples; and - PCR, which is based on amplification of selected segments of the HCMV genome and its hybridization. However, these methods are disadvantageous to be routinely used in clinical diagnosis as point of care because they require a long time to perform or are costly. Thus, there is a need to develop a method which is fast, effective and inexpensive for this virus diagnosis. As an alternative, the use of capture antibodies against the envelope glycoproteins of HCMV open the possibility of faster immunochemical methods. Glycoprotein B of HCMV (gB) is the dominant antigen in the envelope of HCMV, being possible its determination in body fluids like urine and saliva, where viral loads are higher. In consequence, the development of new methods based on the accurate detection of gB in body fluids, is of great interest. In recent years, electrochemical biosensors were widely used to determine various substances with different properties and for continuous monitoring of biological processes. Bioanalytical assays such as immunoassays (IAs), are also very important in many fields. IAs are based on antibodies ability to form complexes with the corresponding antigen, making them highly specific and selective. Thus, electrochemical immunoassays offer enhanced sensitivities and reduced instrumentation costs compared to their counterparts using other transducing elements. Also, screen-printed electrodes (SPE) contribute to develop miniaturized, easy to handle and reliable IAs devices. In addition, SPEs allow for a high-volume production of electrode systems with uniform size and geometry, ensuring measurement reproducibility at low cost. They are also very versatile, since a wide range of designs and materials can be applied in their construction. The present work describes the development of an alternative method for HCMV gB detection and quantification. It is intended the development of an immunosensor to quantify the presence of gB in urine samples. For the construction of this device we made use of a sandwich type immunoassay, wherein HCMV gB is sandwiched between a primary antibody, previously immobilized on a solid surface, and a labelled secondary antibody. Sandwich immunoassays are currently the most commonly and successfully used, mainly due to their high sensitivity and minimized background signal. Moreover, they can be performed on any kind of sensing surface, being the main criterion for these assays the availability of two antibodies with different binding sites on the target antigens. Three different immunoassays were developed. The first one was an electrochemical immunoassay, gB detection was carried out over electrochemical stripping analysis of silver nanoparticles quantitatively deposited on the immunosensor through catalysis by nanogold labels. Capture anti-gB antibodies were absorbed on screen-printed carbon electrodes, and a secondary anti-gB antibody labelled with gold nanoparticles. Nevertheless, the reproducibility of the method (RSDs ≈ 12%) was not very good owing to the random immobilization of the primary antibody on the working electrode, which resulted in small efficiency of antigen detection. Contributing to the low observed RSD was also the nonspecific deposition of silver on the sensor surface. For these reasons, it was decided the development of another approach to overcome the observed limitations. A spectrophotometric magnetic particle-based enzyme immunoassays (mpEIA) was constructed. The use of magnetic beads (MBs) functionalized with protein G (MBs-prG) as solid surface for primary antibody (mAb1) immobilization allows its oriented attachment, resulting in a more effective recognition of gB. Additionally, they improve the affinity interaction thanks to a faster assay kinetics of the dispersed beads in urine samples. The results obtained with this spectrophotometric mpEIA compared favorably to those obtained in other reports of gB detection in terms of analytical performance. Despite the advantages, ELISA readers cannot be applied as portable devices to make in situ measurements. It was then proposed an adaptation to electrochemical transduction on screen-printed electrodes. This variation aimed the achievement of a simple, sensitive, disposable and portable device. It was maintained the immunoassay scheme based on the analyte protein gB sandwiched between the primary monoclonal antibody and the secondary anti-gB-HCMV HRP labelled antibody. Similarly, magnetic particles functionalized with protein G (MBs-prG), were used. The developed immunosensor was shown to be a portable, fast, accurate, rigorous, low cost and an effective method of detecting gB in human urine samples for the valuable diagnosis/screening of HCMV infections.O citomegalovírus humano (HCMV) é o maior vírus da família Herpesviridae e da subfamília β-herpesviridae. Como em todos os vírus herpes, a infeção pelo HCMV resulta no estabelecimento de uma infeção latente ao longo da vida do hospedeiro. Assim, sempre que uma pessoa é infetada, o vírus persiste num estado de latência celular, no qual as células infetadas não produzem nenhuma partícula infeciosa do vírus, mas retêm o seu genoma completo, tendo potencial para começar a produzir partículas virais mais tarde. Após infeção primária, o HCMV é excretado em fluidos corporais, como urina, sangue, saliva, lágrimas, secreções vaginais e cervicais, sêmen e leite materno. Este processo pode durar de meses a anos. Dessa forma, o HCMV pode ser transmitido por via oral, congénita, sexual, através da exposição à urina, por transfusão de sangue e transplante de órgãos ou medula óssea, sendo extremamente difícil identificar a sua via de transmissão. O HCMV é considerado um vírus de paradoxos, pois este pode ser um potencial assassino ou um companheiro silencioso para toda a vida. Isto deve-se ao facto de a infeção pelo HCMV não induzir doença evidente em portadores saudáveis, devido a um controle imunológico efetivo, contudo a infeção pode ser grave e até fatal em indivíduos imunocomprometidos, como é o caso de transplantados, infetados pelo vírus da imunodeficiência humana (HIV) e aqueles com um sistema imunológico imaturo, como fetos e recém-nascidos. O HCMV também é considerado um dos mais bem-sucedidos parasitas, pois pode ser encontrado tanto em sociedades industrializadas e desenvolvidas como em grupos indígenas isolados, sendo a infeção por este vírus relativamente comum entre mulheres em idade reprodutiva, com seroprevalência variando de 45 a 100%. O diagnóstico da infeção por HCMV permanece controverso, pois é difícil separar os pacientes assintomáticos (mas que excretam HCMV em fluidos corporais) e que poderão vir a necessitar de terapia, de pacientes com doença sintomática (pneumonia ou retinite). Atualmente, os métodos laboratoriais para o diagnóstico da infeção por HCMV podem ser divididos em técnicas sorológicas e virológicas. Os métodos sorológicos são usados principalmente para avaliar os anticorpos do doador ou do recetor em situações de transplante e prever o risco de os pacientes imunocomprometidos virem a desenvolver doença sintomática. Por outro lado, o diagnóstico virológico da doença por HCMV é geralmente baseado no isolamento do vírus por métodos de cultura. Estes métodos podem ser usados mediante a utilização de amostras de sangue, urina, saliva, fezes, lágrimas, leite materno, secreções cervicais e vaginais e sêmen. Os métodos mais comuns para o diagnóstico da infeção por HCMV são então: - testes sorológicos baseados na deteção de IgM e IgG; - a deteção direta de HCMV através de isolamento viral em cultura de fibroblastos e deteção de antigénios virais em amostras de tecido, urina ou saliva; e - PCR, que se baseia na amplificação de fragmentos específicos do genoma do HCMV e sua posterior hibridização. No entanto, estes métodos apresentam alguns inconvenientes na sua aplicação como métodos de triagem em laboratórios de análises clínicas, pois requerem um longo período de tempo até à obtenção de um diagnóstico ou são caros. Assim, existe a necessidade de desenvolver um método que seja rápido, eficaz e barato para o diagnóstico deste vírus, capaz de ser usado em série. Nos últimos anos, os biossensores eletroquímicos foram amplamente utilizados na determinação de variadas substâncias com diferentes propriedades e para a monitorização contínua de processos biológicos. A deteção eletroquímica é usada devido a sua sensibilidade aprimorada e custos de instrumentação reduzidos em comparação com outros métodos de transdução. Para além disto, para desenvolver dispositivos eletroquímicos confiáveis, miniaturizados e gerenciáveis, a tecnologia screen-printing é uma escolha inteligente. Os elétrodos serigrafados (SPE) contribuem para o desenvolvimento de novos biosensores em dispositivos miniaturizados, que apresentam as vantagens acima descritas, permitindo a obtenção de resultados em poucos minutos. Adicionalmente, os SPEs permitem uma produção massiva de sistemas eletródicos com tamanho e geometria uniformes, garantindo reprodutibilidade entre medições a baixo custo. Outra mais-valia destes sensores é o facto de serem descartáveis, o que evita alguns problemas frequentemente associados aos elétrodos tradicionais, como a necessidade de um processo de limpeza. Eles são igualmente bastante versáteis, uma vez que uma ampla gama de designs e materiais podem ser aplicados para na sua construção. Na literatura podemos encontrar relatos do uso de dispositivos de deteção miniaturizados para o reconhecimento eletroquímico de sequências amplificadas de ADN provenientes de HCMV. Num desses trabalhos, baseado em elétrodos serigrafados, o ADN alvo foi adsorvido e hibridado com uma sonda de ADN biotinilada e os híbridos formados foram determinados com estreptavidina conjugada com peroxidase de rábano (HRP). Apesar da amplificação de sinal ter sido conseguida, a atividade do conjugado tem de ser controlada periodicamente devido à estabilidade da enzima. Para superar essa limitação, um outro grupo explorou outra estratégia recorrendo a marcação do ADN com nanopartículas de ouro. Apesar de terem tido melhores resultados, ambos os métodos descritos não descartam a utilização de PCR, o que os torna dispendiosos e inúteis como métodos de triagem. Um sensor piezoelétrico também foi descrito para detetar a glicoproteína do HCMV. Embora a técnica não dependa de ADN amplificado, requer o uso de instrumentação cara. Adicionalmente, um dispositivo de deteção baseado em imunofluorescência foi desenvolvido por outro grupo, aqui a amostra biológica é aplicada sobre uma superfície de ouro revestida com anticorpos específicos para HCMV (se presente em amostras biológicas, o HCMV é aprisionado na superfície deste). Ensaios positivos e negativos eram discriminados pelo uso de uma sonda fluorescente. A principal desvantagem deste dispositivo é a baixa sensibilidade que compromete a sua aplicabilidade em amostras com baixas cargas virais. Recentemente, foi ainda proposto um imunoensaio para a deteção do antígeno pp65 do HCMV utilizando HPR e nanopartículas de Pt-Pd funcionalizadas com single-walled nanohorns de carbono. A abordagem permitiu a deteção rápida de HCMV, no entanto, o uso de elétrodos de carbono vítreo não é uma alternativa prática para um método de triagem. O presente trabalho descreve o desenvolvimento de um método alternativo para a deteção e quantificação de HCMV gB. O objetivo é construir um imunossensor que determine a presença de gB em amostras de urina. O uso de anticorpos de captura contra as glicoproteínas do envelope do HCMV abre a possibilidade para o desenvolvimento de novos métodos de análise imunoquímica. A glicoproteína B do HCMV (gB) é uma glicoproteína viral que desempenha um papel crucial na entrada do vírus na célula e surge durante os estágios iniciais de uma infeção pelo mesmo vírus. A gB também é o antigénio dominante presente no envelope do HCMV, sendo possível a sua determinação em fluídos corporais como a urina e saliva, onde as cargas virais são maiores. Como consequência, o desenvolvimento de novos métodos baseados na deteção de gB em fluídos corporais é de grande interesse. Para a construção dos dispositivos, usamos sempre imunoensaios com configuração em sandwich, pois a gB é colocada entre um anticorpo primário, previamente imobilizado numa superfície sólida, e um anticorpo secundário marcado. Os imunoensaios em sandwich são atualmente os mais frequentemente usados, principalmente devido a sua alta sensibilidade e correspondente minimização de interferências. Para além disto, podem ser realizados em qualquer tipo de superfície, sendo o principal critério destes ensaios a disponibilidade de dois anticorpos com sítios de ligação diferentes para o mesmo antigénio-alvo. Durante o decorrer deste trabalho foram desenvolvidos três imunoensaios diferentes. O primeiro foi um imunoensaio eletroquímico. Foram usados anticorpos de captura anti-gB absorvidos em elétrodos de carbono serigrafados e um anticorpo secundário anti-gB marcado com nanopartículas de ouro. A deteção de gB foi realizada por meio da análise eletroquímica de nanopartículas de prata depositadas quantitativamente no imunossensor através de catálise por nanopartículas de ouro, as quais foram utilizadas como marcadores do anticorpo secundário. A reprodutibilidade do método (RSDs de cerca de 12%) não foi muito boa devido à imobilização aleatória do anticorpo primário no elétrodo de trabalho, o que resultou numa pequena eficiência de deteção do antígeno (foram observados baixos sinais considerando a grande quantidade de anticorpo utilizado). Contribui-o também para a baixa RSD observada a deposição não específica de prata na superfície do sensor. Por estas razões, decidiu-se desenvolver outra abordagem para superar as limitações observadas. Desenvolvemos um imunoensaio enzimático espectrofotométrico baseados em partículas magnéticas (mpEIA). O uso de esferas magnéticas (MBs) funcionalizadas com proteína G (MBs-prG) como superfície sólida para a imobilização do anticorpo primário (mAb1) permite a sua fixação orientada, resultando num reconhecimento mais efetivo do gB. Para além disto, estas partículas melhoram a interação de afinidade graças a uma cinética de análise mais rápida. O anticorpo secundário foi marcado com HRP para possibilitar a deteção espectrofotométrica. Os resultados obtidos com este mpEIA espectrofotométrico são favoravelmente comparáveis com outros relatos de deteção de gB em termos de desempenho analítico. No entanto, apesar das vantagens, os leitores ELISA não podem ser aplicados como dispositivos portáteis para fazer medições in situ. Para superar essa limitação, o método mpEIA mencionado acima foi adaptado à transdução eletroquímica recorrendo ao uso de elétrodos serigrafados. Esta variação visou a obtenção de um dispositivo simples, sensível, descartável e portátil. É mantido o esquema de imunoensaio com base na proteína analítica gB intercalada entre um anticorpo monoclonal primário e o anticorpo secundário anti-gB marcado com HRP, que permite igualmente deteção eletroquímica. Da mesma forma, partículas magnéticas funcionalizadas com proteína G (MBs-prG) são usadas para permitir a imobilização orientada ao anticorpo (mAb1). O imunossensor desenvolvido mostrou ser um método portátil, rápido, preciso, rigoroso, de baixo custo e, portanto, eficaz na deteção de gB em amostras de urina humana para a valiosa triagem de infeções por HCMV