A reagentless, disposable biosensor for lactic acid based on a screen-printed carbon electrode containing Meldola's Blue and coated with lactate dehydrogenase, NAD+ and cellulose acetate

Sprules, Steven D.; Hart, John P.; Wring, Stephen A.; Pittson, R.

doi:10.1016/0003-2670(94)00565-4

Cited by 70 publications

(28 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For an image of 500 Â 500 nanometers area, the calculated roughness was only 1.24 nanometers. This is a value much smaller than the observed in screenprinted surfaces [6,18,19] and even for solid electrodes polished by conventional processes. Another important aspect is the crystalline arrangement verified for gold films deposited on compact disks.…”

Section: Microscopic Characteristics Of the Recordable Cdsmentioning

confidence: 71%

Disposable Gold Electrodes with Reproducible Area Using Recordable CDs and Toner Masks

et al. 2006

View full text Add to dashboard Cite

The fabrication and characterization of very cheap disposable gold disk electrodes with reproducible area is reported. The innovation of the proposed procedure is the use of toner masks to define reproducible areas on uniform gold surfaces obtained from recordable compact disks (CD-R). Toner masks are drawn in a laser printer and heat transferred to gold surfaces, defining exactly the electrodes area. The electrochemical behavior of these disposable electrodes was investigated by cyclic voltammetry in Fe(CN) 6 4À solutions. The relative standard deviation for signals obtained from 10 different gold electrodes was below 1 %. The size of the disk electrodes can be easily controlled, as attested by voltammetric responses recorded by using electrodes with radii varying from 0.5 to 3.0 mm. The advantages of using this kind of electrode for analytical measurements of substances that strongly adsorb on the electrode surface such as cysteine are also addressed.

show abstract

Section: Microscopic Characteristics Of the Recordable Cdsmentioning

confidence: 71%

Disposable Gold Electrodes with Reproducible Area Using Recordable CDs and Toner Masks

et al. 2006

View full text Add to dashboard Cite

show abstract

“…In previous research, we successfully co-immobilized lactate dehydrogenase and NADH onto a MB-SPCE to produce a lactate biosensor [7,8], and similarly, alcohol dehydrogenase and the same cofactor to produce an alcohol biosensor [9]. In these cases, the immobilization processes were performed by a simple drop coating procedure; therefore, we considered that this approach might also be applicable to the development of the proposed NH 4 biosensor.…”

Section: Introductionmentioning

confidence: 95%

Development of a Disposable Amperometric NH Biosensor Based on a Chemically Modified Screen-Printed Carbon Electrode Coated with Glutamate Dehydrogenase, 2-Oxoglutarate, and NADH

Hart¹,

Abass

Cowell

et al. 1999

Electroanalysis

View full text Add to dashboard Cite

A screen-printed carbon electrode (SPCE), impregnated with the electrocatalyst Meldola's Blue (MB), has been investigated as the base transducer in a disposable amperometric NH 4 biosensor. The MB-SPCE detects the cofactor NADH when it is polarized at a potential of only 0.05 V (vs. AgaAgCl); electrocatalytic oxidation of the cofactor readily occurs at this potential. The device was converted into an NH 4 biosensor by coating the surface of the MB-SPCE with glutamate dehydrogenase, 2-oxoglutarate and NADH. When ammonium ions are present in the sample solution, a decrease in the anodic current occurs as a result of the enzymatic conversion of 2-oxoglutarate to glutamate which requires NADH. Chronoamperometry was performed on 40 mL aliquots of solutions containing various concentrations of NH 4 . A 30 s incubation period was used, then the potential was stepped from open circuit to 0.05 V (vs. AgaAgCl); response currents were measured from the resulting chronoamperograms at a time of 120 s (t 120s ). The detection limit was found to be about 2 mM with biosensors containing 4.6 U of enzyme. The stability of these biosensors was examined after storage at 4 C in a desiccator containing silica gel; the response was found to be constant for a period of about 29 days. The proposed biosensors were evaluated on samples of unspiked, and spiked, river water; the recovery and precision data indicated that the devices could be expected to give reliable results for the low levels of NH 4 normaly expected in rivers.

show abstract

“…24 The redox behavior and efficient electrocatalytic properties of these organic dyes have been employed for the determination of different substrates such as H 2 O 2 , 25,26 alcohols, 27 lactate, [28][29][30] ammonia, 31 acid formic 32 and enzymes like aspartate aminotransferase 33 and horseradish peroxidase. 26 The optimization of the experimental conditions that leads to the best values of the reversibility of an electrochemical system requires the study of several variables, such as kind of electrode, pH of the solution, concentration of supporting electrolyte, scan rate, etc.…”

Section: Introductionmentioning

confidence: 99%

Cationic dyes immobilized on cellulose acetate surface modified with titanium dioxide: factorial design and an application as sensor for NADH

Hoffmann¹,

Dias²,

Benvenutti³

et al. 2007

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

As propriedades eletroquímicas dos corantes catiônicos, azul de meldola e azul de toluidina, imobilizados na superfície do acetato de celulose modificado com dióxido de titânio foram investigadas por voltametria cíclica. Os materiais sintetizados foram empregados como eletrodos de pasta de carbono. As propriedades mediadoras redox dos eletrodos modificados quimicamente com azul de meldola e azul de toluidina foram otimizadas utilizando um planejamento fatorial consistindo de dois níveis e quatro fatores com dois pseudo-pontos centrais (n=20 experimentos). A análise fatorial foi realizada para investigar as melhores condições de reversibilidade do processo redox tais como uma diminuição na separação entre os picos de potenciais anódico e catódico e razão de corrente próxima da unidade. Os fatores que apresentaram efeitos significantes na otimização global do sistema e que permitiram alcançar as melhores condições de reversibilidade de transferência de elétrons foram os fatores principais velocidade de varredura e tipo de eletrodo (azul de meldola ou azul de toluidina) além dos fatores de interação concentração do KCl × tipo de eletrodo (B×D) e a interação pH × [KCl] × velocidade de varredura (A×B×C). As melhores condições de reversibilidade eletroquímica obtidas foram: o eletrodo CA-TiO 2 -MB, KCl 1,0 mol L -1 como eletrólito suporte e velocidade de varredura de 10,0 mV s -1 . Adicionalmente, o eletrodo modificado CA-TiO 2 -MB foi testado como sensor amperométrico para a determinação de NADH com um limite de detecção de 0,1 µmol L -1 .The electrochemical properties of meldola blue and toluidine blue cationic dyes immobilized on cellulose acetate surface modified with titanium dioxide were investigated by cyclic voltammetry. The materials synthesized were employed as carbon paste electrodes. The redox mediator properties of the meldola blue and toluidine blue chemically modified electrodes were optimized using a factorial design, consisting of two levels and four factors with two pseudo-central points (n= 20 experiments). The factorial analysis was carried out by searching for better reversibility of the redox process, such as the lowest separation between anodic and cathodic potential peaks and a current ratio near unity. The factors that presented significant effects on the overall optimization of the system to achieve the best conditions of the reversibility of electron transfer were the main factors scan rate and type of electrode (meldola blue or toluidine blue), besides the interaction factors KCl concentration × type of electrode (B×D) and the pH × [KCl] concentration × scan rate (A×B×C) interaction. The best electrochemical reversibility conditions obtained were: using the CA-TiO 2 -MB electrode, 1.0 mol L -1 KCl as supporting electrolyte, at scan rate of 10.0 mV s -1 . Afterwards, the CA-TiO 2 -MB modified electrode was tested as an amperometric sensor for the determination of NADH, with a detection limit of 0.1 µmol L -1 .Keywords: meldola blue, toluidine blue, modified cellulose acetate, factorial desig...

show abstract

A reagentless, disposable biosensor for lactic acid based on a screen-printed carbon electrode containing Meldola's Blue and coated with lactate dehydrogenase, NAD+ and cellulose acetate

Cited by 70 publications

References 14 publications

Disposable Gold Electrodes with Reproducible Area Using Recordable CDs and Toner Masks

Disposable Gold Electrodes with Reproducible Area Using Recordable CDs and Toner Masks

Development of a Disposable Amperometric NH Biosensor Based on a Chemically Modified Screen-Printed Carbon Electrode Coated with Glutamate Dehydrogenase, 2-Oxoglutarate, and NADH

Cationic dyes immobilized on cellulose acetate surface modified with titanium dioxide: factorial design and an application as sensor for NADH

Contact Info

Product

Resources

About