Biosensors based on gold nanostructures

Abstract

O presente trabalho de revisão aborda os mais recentes avanços na tecnologia de biossensores alcançados através da montagem de biomoléculas associada com nanopartículas de ouro na construção de dispositivos analíticos. Esta revisão está dividida de acordo com a biomolécula empregada no desenvolvimento de biossensores: (i) compostos imunológicos; (ii) DNA/RNA funcionais; e (iii) enzimas e proteínas Heme. A fim de facilitar a compreensão, cada seção foi subdividida de acordo com o modo de transdução. Os imunossensores contendo nanopartículas de ouro têm uma ampla gama de aplicações nos campos alimentício, ambiental, farmacêutico, químico e de diagnósticos clínicos. As nanopartículas foram empregadas para melhorar o sinal analítico ou a imobilização dos imunocompostos. Em outra seção, os biossensores DNA/ RNA empregando nanoestruturas de ouro como labels e biossensores label-free associados a nanoestruturas de ouro como transdutores foram sistematicamente relatados para a rápida identificação de patógenos, espécies de interesse ambiental e diagnóstico clínico. A inclusão de nanopartículas de ouro em eletrodos modificados aumenta a transferência de elétrons entre o transdutor e a biomolécula proporcionando um melhor desempenho quando enzimas e proteínas redox heme são usados. Biossensores para a detecção e quantificação de glicose e peróxido de hidrogênio foram também discutidos.The present review discusses the latest advances in biosensor technology achieved by the assembly of biomolecules associated with gold nanoparticles in analytical devices. This review is divided in sections according to the biomolecule employed in the biosensor development: (i) immunocompounds; (ii) DNA/RNA and functional DNA/RNA; and (iii) enzymes and Heme proteins. In order to facilitate the comprehension each section was subdivided according to the transduction mode. Gold nanoparticles based immunosensors have a wide range of applications in food, environmental, pharmaceutical, chemistry and clinical diagnostics. The nanoparticles were employed to improve whether the analytical signal or the immunocompounds immobilization. In another section, biosensors based on DNA/RNA biomolecules employing gold nanostructures as labels and label-free funtional DNA/RNA biosensors associated to gold nanostructures as tranducers were systematically reported for rapid identification of pathogens, species of environmental interest and clinical diagnostics, respectively. The inclusion of gold nanoparticles in modified electrodes itself enhances the electron transfer between the transducer and biomolecules leading to improved bioanalytical devices when redox enzymes and heme proteins are used. Biosensors for the detection and quantification of glucose and hydrogen peroxide are discussed as well.

Simultaneous Determination of Different Phenolic Compounds Using Electrochemical Biosensor and Multivariate Calibration

“…36 The gain in surface area contributes to immobilization of higher amounts of enzyme over the exposed surface, which explains the increase in sensitivity of the apparatus as expected. Besides, nanoparticles can also contribute with the rate of electron transfer 37 between electrode and active site of the enzyme, making an important feature for electroanalytical determinations. The effect of the nanoparticles was evaluated only for guaiacol, because this phenol produces a much lower electrochemical signal than hydroquinone, showing an increase in the detectability of this contaminant.…”

Biomedical applications of nanobiosensors: the state-of-the-art

“…Nanobiosensors have been emerging with fast pace in the field of biomedical, agricultural and environmental sciences 138,139 and with special emphasis with layer-bylayer films [140][141][142] and with the pioneer research of Brolo and co-workers. 143 The applications in the field of detection of fatal diseases like cancer and diabetes have brought nanobiosensors in the fore front of research.…”

DNA polymorphism sensitive impedimetric detection on gold-nanoislands modified electrodes

“…There is a great demand for new materials and protocols for developing novel analytical devices to be employed in the sensitive and specific detection of DNA sequences [1][2][3][4][5]. DNA biosensors (or genosensors) are devices that combine DNA strands as biorecognition element and a transducer that converts the biorecognition event into a measurable analytical signal [6].…”

“…To represent a valid alternative to classical techniques for DNA analysis, a genosensor should possess specific features like simplicity, portability, low cost and fast response, and this is normally accomplished with electrochemical transduction. So far, the most used electrochemical transducers for DNA immobilization and detection have been mainly based on gold [4,7] and carbon materials [3,[8][9][10].…”