Biossensores elétricos para a detecção não amplificada de RNA viral: uma revisão
Data
2023-07-01
Autores
Parassol, Brenda Garcia 
Orientadores
Vieira, Nirton Cristi Silva
Tipo
Trabalho de conclusão de curso
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Os vírus são microrganismos causadores de diversas doenças em todo o mundo. A recente pandemia de COVID-19 mostrou a necessidade de testes rápidos e confiáveis para confirmar infecções virais, visando o rápido isolamento e tratamento adequado. O teste padrão-ouro para o diagnóstico de doenças virais é o RT-PCR, que identifica partes do genoma viral por meio da detecção de sequências de ácidos nucléicos. No entanto, o RT-PCR ou testes semelhantes, como o RT-LAMP, usam vários tipos de equipamentos, envolvem várias etapas para o preparo da amostra e precisam de pessoal treinado, além de serem demorados e caros. Por outro lado, os biossensores são dispositivos analíticos promissores para a detecção de ácidos nucléicos. Os biossensores elétricos são a escolha prometida para aplicações diagnósticas, pois garantem alta sensibilidade, baixo custo, fabricação em larga escala e curto tempo para apresentar o resultado. No entanto, até o momento, não existem no mercado biossensores elétricos para detecção de ácidos nucléicos, principalmente o ácido ribonucléico (RNA), que é o material genético de vários vírus, como Dengue, Hepatite C, Ebola, SARS, etc. uma revisão da literatura sobre o desenvolvimento de biossensores para a detecção não amplificada de sequências de RNA de vírus. Primeiramente, é possível identificar os tipos de imobilização do DNA de fita simples (ácido desoxirribonucléico) nos transdutores. Em biossensores, o ssDNA é uma sequência de reconhecimento específica para o reconhecimento do RNA alvo. Existem também outros elementos de reconhecimento de RNA, como a recente tecnologia CRISPR-Cas. Em biossensores elétricos, quando ocorre a hibridização ssDNA/RNA, há uma mudança no campo elétrico local, gerando um sinal captado pelo transdutor elétrico. Em seguida, são apresentados os estudos já realizados que obtiveram resultados favoráveis de detecção de RNA, incluindo eletrodos de alumínio interdigitados para detecção do vírus Zika, transistores de efeito de campo (FETs) para COVID-19 e outras doenças virais. Por fim, são apresentadas as dificuldades e tendências futuras desses biossensores que prometem ser a futura detecção de infecções virais.
Viruses are microorganisms that cause various diseases worldwide. The recent COVID-19 pandemic has shown the need for rapid and reliable tests to confirm viral infections, aiming at rapid isolation and adequate treatment. The gold standard test for diagnosing viral diseases is RT-PCR, which identifies parts of the viral genome by detecting nucleic acid sequences. However, RT-PCR or similar tests such as RT-LAMP use several types of equipment, involve multiple steps for sample preparation and need trained personnel, and are time-consuming and expensive. On the other hand, biosensors are promising analytical devices for detecting nucleic acids. Electrical biosensors are promised choice for diagnostic appli-cations because they guarantee high sensitivity, low cost, and fabrication on a large scale, and a short time to present the result. However, so far, no electrical biosensors are available on the market for detecting nucleic acids, especially ribonucleic acid (RNA), which is the genetic material of several viruses, like Dengue, Hepatitis C, Ebola, SARS, etc. The present study involves a literature review on developing biosensors for the unamplified detection of RNA sequences from viruses. First, it is possible to identify the types of single-stranded DNA (deoxy-ribonucleic acid) immobilization on the transducers. In biosen-sors, ssDNA is a specific recognition sequence for target RNA recognition. There are also other elements of RNA recognition, such as the recent CRISPR-Cas technology. In electrical bio-sensors, when ssDNA/RNA hybridization occurs, there is a change in the local electric field, generating a signal sensed by the electrical transducer. Then, the studies already carried out that obtained favorable RNA detection results are presented, including interdigitated aluminum electrodes for Zika virus detection, field-effect transistors (FETs) for COVID-19, and other viruses diseases. Finally, the difficulties and future trends for these biosensors that promise to be the future detection of viral infections are presented.
Viruses are microorganisms that cause various diseases worldwide. The recent COVID-19 pandemic has shown the need for rapid and reliable tests to confirm viral infections, aiming at rapid isolation and adequate treatment. The gold standard test for diagnosing viral diseases is RT-PCR, which identifies parts of the viral genome by detecting nucleic acid sequences. However, RT-PCR or similar tests such as RT-LAMP use several types of equipment, involve multiple steps for sample preparation and need trained personnel, and are time-consuming and expensive. On the other hand, biosensors are promising analytical devices for detecting nucleic acids. Electrical biosensors are promised choice for diagnostic appli-cations because they guarantee high sensitivity, low cost, and fabrication on a large scale, and a short time to present the result. However, so far, no electrical biosensors are available on the market for detecting nucleic acids, especially ribonucleic acid (RNA), which is the genetic material of several viruses, like Dengue, Hepatitis C, Ebola, SARS, etc. The present study involves a literature review on developing biosensors for the unamplified detection of RNA sequences from viruses. First, it is possible to identify the types of single-stranded DNA (deoxy-ribonucleic acid) immobilization on the transducers. In biosen-sors, ssDNA is a specific recognition sequence for target RNA recognition. There are also other elements of RNA recognition, such as the recent CRISPR-Cas technology. In electrical bio-sensors, when ssDNA/RNA hybridization occurs, there is a change in the local electric field, generating a signal sensed by the electrical transducer. Then, the studies already carried out that obtained favorable RNA detection results are presented, including interdigitated aluminum electrodes for Zika virus detection, field-effect transistors (FETs) for COVID-19, and other viruses diseases. Finally, the difficulties and future trends for these biosensors that promise to be the future detection of viral infections are presented.