An electronic tongue using polypyrrole and polyaniline

Riul, Antonio; Soto, Álvaro Moreno; Mello, Sarita V.; Bone, Stephen; Taylor, David; Mattoso, Luiz H. C.

doi:10.1016/s0379-6779(02)00107-8

Cited by 216 publications

(138 citation statements)

References 29 publications

Supporting

Mentioning

120

Contrasting

Unclassified

Order By: Relevance

“…The latter contains three components: the geometric capacitance of the electrode immersed in an electrolyte (CPEg), the electrical double layer capacitance (CPEd), and the total resistance of the electrolyte represented by (1/Rd+1/Rt), where Rd is the electrical double layer resistance and Rt is the charge transfer though the interface electrolyte/film. The electrical response is governed by different physicochemical phenomena depending on the frequency range, as follows [49]: At the low-frequency region (10 0 -10 2 Hz), impedance is mainly related to the formation of an electrical double layer at the film/solution interface [49]; in the mid-frequency region (10 2 -10 5 Hz), it is related to the properties of the film coating the electrode [49], and at the highfrequency region (>10 5 Hz), the impedance response is dominated by the geometric capacitance of the interdigitated electrodes [49] and by the dielectric constant of the solution [50].…”

Section: Sensing Atrazine With Impedance Spectroscopymentioning

confidence: 99%

Detection of trace levels of atrazine using surface-enhanced Raman scattering and information visualization

et al. 2014

View full text Add to dashboard Cite

The detection of trace amounts of pesticides is essential for the quality control of waters, particularly with their inevitable increasing use with the growing demand for food. In this study, we report on the detection of atrazine, a highly toxic herbicide, down to 5×10−12 M, which is sufficient to monitor the quality of drinking water even according to the most stringent international regulations. Such detection was performed with surface-enhanced Raman scattering (SERS) in atrazine incorporated into silver nanoparticles (AgNPs) colloids, with the SERS spectra being treated with Sammon's mapping, an information visualization technique. In addition to providing a fingerprint of the atrazine molecules, SERS is advantageous in comparison with impedance spectroscopy and cyclic voltammetry applied to a sensor array of units made with layer-by-layer (LbL) films containing AgNPs and AuNPs. The combined use of SERS and information visualization methods is promising for monitoring water quality with regard to other pesticides, which may even approach single molecule detection.

show abstract

Section: Sensing Atrazine With Impedance Spectroscopymentioning

confidence: 99%

Detection of trace levels of atrazine using surface-enhanced Raman scattering and information visualization

et al. 2014

View full text Add to dashboard Cite

show abstract

“…In the literature, physical techniques have been used for 10 years to study different properties of coffee, such as: quantification of caffeine in coffee beverage via UV-Vis spectrometry (BELAYA et al, 2008); conservation states of caffeinated samples via UV-Vis spectrometry (SOUTO et al, 2010), evaluation of green coffee bean quality using near infrared spectroscopy (SANTOS et al, 2012); authenticity of Instant Coffee via proton nuclear magnetic resonance spectroscopy (CHARLTON;FARRINGTON;BRERETON, 2002); differentiation of Arabica and Robusta varieties of coffee with the electronic Aroma-sensing Device (FREITAS; PARREIRA; VILAS-BOAS, 2001); differentiation of coffee flavor via electronic tongue (RIUL et al, 2003). But none of these related the coffee beverage quality with parameters measured by these physical techniques.…”

Section: Introductionmentioning

confidence: 99%

Correlation between antioxidant activity and coffee beverage quality by Electron Spin Resonance Spectroscopic

et al. 2013

View full text Add to dashboard Cite

Brazil is the largest producer of coffee in the world and coffee prices are directly linked to grain quality. In this work, the antioxidant activity of coffee was related to its quality through Electron Spin Resonance Spectroscopy (ESR), as an attempt to establish a non-subjective method to classify the grain quality. For that purpose, the IC50 and temporal monitoring of its nonoxidized fraction were determined for three bean qualities: Soft (High), Hard (Medium) and Rio (Low). Methanolic solution of 2,2-difenil-1-picril-hidrazila (DPPH), that has a stable radical and a JEOL FA-200 (X-Band) spectrometer were used for these tests. The temporal monitoring of reaction between radical and coffee was performed. The rate of reduced or of antioxidated radicals was determined on time and for each coffee beverage quality were found different slopes of curve: Soft (0.32±0.02), Hard (0.47±0.02) and Rio (0.60±0.02). The IC50 result of Rio quality (2.7 ± 0.9) was different from the Soft (7.8 ± 1.9) and Hard (6.5 ± 1.5) values, but there was no difference between the High and Medium results due to the uncertainty associated. Therefore the results found, mainly for monitoring temporal, establish a new quantitative methodology for classifying the coffee beverage quality.Index terms: Classify, method, IC50. RESUMOO Brasil é o maior produtor mundial de café e os preços dessa mercadoria são diretamente influenciados pela qualidade dos grãos. A atividade antioxidante do café foi relacionada com a sua qualidade de bebida através de Espectroscopia de Ressonância de spin eletrônico (ESR), como uma tentativa de estabelecer um método não subjetivo para classificar a qualidade do grão. O teste IC50 e o monitoramento temporal da fração do radical DPPH não reduzida pelas três qualidades de bebida Mole (Alta), Dura (Média) e Rio (Baixa) foram determinados. Uma solução metanólica de 2,2-difenil-1-picril-hidrazila (DPPH), que tem um radical estável e um espectrômetro JEOL FA-200 (banda-X) foram utilizados para os ensaios. O monitoramento temporal da reação entre o radical e o café foi registrado por espectros de ESR. A taxa de radicais reduzidos ou antioxidados foi determinada no tempo e para cada qualidade da bebida do café foram encontrados diferentes inclinações da curva: Mole (0,32 ± 0,02), Dura (0,47 ± 0,02) e Rio (0,60 ± 0,02). O resultado de IC50 de qualidade Baixa (2,7 ± 0,9) foi diferente dos valores de Mole (7,8 ± 1,9) e Dura (6,5 ± 1,5), mas não existiu nenhuma diferença entre os resultados de Mole e Dura, em razão da incerteza associada. Portanto, os resultados encontrados, principalmente para o monitoramento temporal, estabelecem uma nova metodologia quantitativa para classificar a qualidade de bebida dos grãos de café.Termos para indexação: Classificação, método, IC50.

show abstract

“…Potential applications of conducting polymers such as polyaniline (PANI), polypyrrole (PPY) and poly thiophene (PTP) in batteries [1][2][3][4], electronic devices [5][6][7][8], displays [9], sensors [10], electrodes [11], electronic tongue [12], nanotubes or nanorods [13] and molecular electronics [14][15][16][17] are well known. There are mainly two routes for the preparation of CPs: chemical and electrochemical polymerization [18,19].…”

Section: Introductionmentioning

confidence: 99%

The Electrochemical Synthesis and Corrosion Inhibitive Nature of Di N-Propyl Malonic Acid Doped Poly N –Methyl Aniline Coating On Stainless Steel

Kumar¹

2013

IOSR-JAC

View full text Add to dashboard Cite

An electronic tongue using polypyrrole and polyaniline

Cited by 216 publications

References 29 publications

Detection of trace levels of atrazine using surface-enhanced Raman scattering and information visualization

Detection of trace levels of atrazine using surface-enhanced Raman scattering and information visualization

Correlation between antioxidant activity and coffee beverage quality by Electron Spin Resonance Spectroscopic

The Electrochemical Synthesis and Corrosion Inhibitive Nature of Di N-Propyl Malonic Acid Doped Poly N –Methyl Aniline Coating On Stainless Steel

Contact Info

Product

Resources

About