• Journal of Biosystems Engineering
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• v.28 no.5
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• pp.465-468
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• 2003

A microdialysis coupled flow injection amperometric biosensor was calibrated to measure the concentration of glucose using 7 standard samples from 10ml to 70ml of glucose solution. The output of the sensor increased linearly with an increase in the glucose concentration with an $R^2$ correlation of 0.99. The amperometric biosensor was then applied to measure the. glucose concentration of 2 commercial samples(Orange and Pineapple juice) and the results compared with HPLC. Around 12% error was observed in glucose concentration measurements of the samples analyzed. The sensor has potential in rapid measurement once the calibration is done. Potential for on-line sensing is also discussed.

• Journal of Biosystems Engineering
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• v.29 no.6 s.107
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• pp.553-557
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• 2004

A microdialysis coupled flow injection amperometric $({\mu}FIA)$ biosensor was calibrated to measure the concentration of sucrose using 11 standard samples from 2 ml to 70 ml of sucrose solution. The output of the sensor increased linearly with an increase in the sucrose concentration with an $r^2$ correlation of 0.99. The amperometric biosensor was then applied to measure the sucrose concentration of 4 commercial samples (Orange and Pineapple juices, Pepsi, Sprite) and the results compared with those by HPLC. Around $20\~30\%$ error was observed in sucrose concentration measurements of the samples analyzed. The sensor has potential in rapid measurement once the calibration is done. Potential for on-line sensing is also discussed.

• Analytical Science and Technology
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• v.7 no.2
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• pp.149-153
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• 1994

An amperometric sensor for L-ascorbic acid(AA) in methanol media has been made by immobilizing squash-tissues on a graphite rod disk. A detection limit of the electrode was $2{\times}10^{-6}M$ L-ascorbic acid. In comparison with an isolated enzyme based ascorbate oxidase(AO) electrode, the plant-tissue electrode offered high biocatalytic stability and activity and extremely low cost. The electrode has a useful lifetime of 1 week.

• Journal of Sensor Science and Technology
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• v.17 no.1
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• pp.29-34
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• 2008

A new disposable amperometric tri-enzyme biosensor for the detection of paracetamol has been developed. The paracetamol sensors developed uses horseradish peroxidase modified screen-printed carbon electrodes (HRP-SPCEs) coupled with immobilized enzymes, tyrosinase and aryl acylamidase, prepared using a poly (vinyl alcohol) bearing styrylpyridinium groups (PVA-SbQ) matrix. Optimization of the experimental parameters has been performed and the paracetamol biosensor showed detection limit for paracetamol is as low as $100{\mu}M$ and the sensitivity of the sensor is $1.46nA{\mu}M^{-1}cm^{-2}$.

• Journal of the Korean Chemical Society
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• v.48 no.6
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• pp.654-658
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• 2004

• Journal of the East Asian Society of Dietary Life
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• v.20 no.5
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• pp.735-742
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• 2010

Biogenic amines are synthesized by microbial decarboxylation for the putrefaction or fermentation of foods containing protein. Although biogenic amines such as histamine, tyramine, and putrescine are required for many physiological functions in humans and animals, consumption of high amounts of biogenic amines can cause toxicological effects, including serious gastrointestinal, cutaneous, hemodynamic, and neurological symptoms. In this study, a novel amperometric biosensor wasdeveloped to detect biogenic amines. The biosensor consisted of a working electrode, a reference electrode, a counter electrode, an enzyme reactor with immobilized diamine oxidase, an injector, a peristaltic pump and a potentiostat. A working electrode was fabricated with a glassy carbon electrode (GCE) by coating functionalized multi-walled carbon nanotubes (MWCNT-$NH_2$) and by electrodepositing Prussian blue (PB) to enhance electrical conductivity. A sensor system with PB/MWCNT-$NH_2$/GCE showed linearity in the range of $0.5 {\mu}M{\sim}100 {\mu}M$ hydrogen peroxide with a detection limit of $0.5 {\mu}M$. The responses for tyramine, 2-phenylethylamine, and tryptamine were 95%, 75%, and 70% compared to that of histamine, respectively. These results imply that the biosensor system can be applied to the quantitative measurement of biogenic amines.

• Bulletin of the Korean Chemical Society
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• v.27 no.1
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• pp.65-70
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• 2006

An amperometric glucose biosensor has been developed based on the use of the nanoporous composite film of sol-gel-derived zirconia and perfluorosulfonated ionomer, Nafion, for the encapsulation of glucose oxidase (GOx) on a platinized glassy carbon electrode. Zirconium isopropoxide (ZrOPr) was used as a sol-gel precursor for the preparation of zirconia/Nafion composite film and the performance of the resulting glucose biosensor was tuned by controlling the water content in the acid-catalyzed hydrolysis of sol-gel stock solution. The presence of Nafion polymer in the sol-gel-derived zirconia in the biosensor resulted in faster response time and higher sensitivity compared to those obtained at the pure zirconia- and pure Nafion-based biosensors. Because of the nanoporous nature of the composite film, the glucose biosensor based on the zirconia/Nafion composite film can reach 95% of steady-state current less than 5 s. In addition, the biosensor responds to glucose linearly in the range of 0.03-15.08 mM with a sensitivity of 3.40 $\mu$A/mM and the detection limit of 0.037 mM (S/N = 3). Moreover, the biosensor exhibited good sensor-to-sensor reproducibility (~5%) and long-term stability (90% of its original activity retained after 4 weeks) when stored in 50 mM phosphate buffer at pH 7 at 4 ${^{\circ}C}$.

• Food Science and Biotechnology
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• v.14 no.6
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• pp.743-746
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• 2005

A dipstick-type immunochemical biosensor for the detection of the organophosphorus insecticide fenthion was developed using a screen-printed electrode system as an amperometric transducer with polyclonal antibodies against fenthion as a bioreceptor. The assay of the biosensor involved competition between the pesticide in the sample and pesticide-glucose oxidase conjugate for binding to the antibody immobilized on the membrane. This was followed by measurement of the activity of the bound enzyme by the supply of the enzyme substrate (glucose) and amperometric determination of the enzyme reaction product ($H_2O_2$). The activity of the bound enzyme was inversely proportional to the concentration of pesticide. The optimized sensor system showed a linear response against the logarithm of the pesticide concentration ranging from $10^{-2}$ to $10^3\;{\mu}g/L$.

• Journal of the Korean Electrochemical Society
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• v.5 no.4
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• pp.212-215
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• 2002

A superoxide dismutase (SOD)-based superoxide ion $(O_2^-)$ sensor was fabricated by immobilizing SOD on a self-assembled monolayer (SAM) of 3-mercaptopropionic acid (MPA) which was prepared on a gold electrode. The SAM of MPA was found to function as an effective promoter for the electrode reaction of SOD. The amperometric response to $(O_2^-)$ was monitored at 300mV and -100mV vs. Ag/ Agel in 5mM phosphate buffer solution containing $KO_2$. The sensor was proved to have a high sensitivity, selectivity and short response time (<5 s) and negligible interference.

• Journal of the Korean Chemical Society
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• v.41 no.7
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• pp.343-350
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• 1997

The response characteristics of a new biosensor, which was developed by co-immobilisation of chicken liver tissue and ferrocene in a carbon paste matrix for the amperometric determination of hydrogen peroxide, was evaluated. In the range of electrode potential observed ( - 0.5∼ + 0.05 V vs Ag/AgCl), the bioelectrode showed the response time ($t_{95%}$) as low as 13 sec and the detection limit of $5.1{\times}10^{-5}$ M, and exhibited a good selectivity in the case of the addition of the possible interferents tested. Also it offered a high biocatalytic stability and opened up the possibility for the construction of a mediatorless biosensor.