• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.1-14
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• 2023

The overuse of pesticides in agricultural sectors exposes people to food contamination. Pesticides are toxic to humans and can have both acute and chronic health effects. To protect food consumers from the adverse effects of pesticides, a rapid monitoring system of the residues is in dire need. Molecularly imprinted polymer (MIP) on a screen-printed electrode (SPE) is a leading and promising electrochemical sensing approach for the detection of several residues including pesticides. Despite the huge development in analytical instrumentation developed for contaminant detection in recent years such as HPLC and GC/MS, these conventional techniques are time-consuming and labor-intensive. Additionally, the imprinted SPE detection system offers a simple portable setup where all electrodes are integrated into a single strip, and a more affordable approach compared to MIP attached to traditional rod electrodes. Recently, numerous reviews have been published on the production and sensing applications of MIPs however, the research field lacks reviews on the use of MIPs on electrochemical sensors utilizing the SPE technology. This paper presents a distinguished overview of the MIP technique used on bare and modified SPEs for the detection of pesticides from four recent publications which are malathion, chlorpyrifos, paraoxon and cyhexatin. Different molecular imprint routes were used to prepare these biomimetic sensors including solution polymerization, thermal polymerization, and electropolymerization. The unique characteristics of each MIP-modified SPE are discussed and the comparison among the findings of the papers is critically reviewed.

• 센서학회지
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• 제32권6호
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• pp.412-417
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• 2023

There is increasing interest in the rapid and highly sensitive monitoring of cell viability in biological and toxicological research. Conventional methods depend on optical assays using Water Soluble Tetrazolium-8 (WST-8) or 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay, which requires a large volume of samples and special instruments, necessitating shipment of clinical samples to laboratories. This paper reports on the development of a rapid and sensitive electrochemical (EC) sensor using screen printed electrode (SPE) and surface modification using 4'-mercapto-N-phenylquinone diamine (4'-NPQD), as double electron mediators, for monitoring cell viability via the measurement of nicotinamide adenine dinucleotide (NADH). We used the sensor to observe the viability of MCF-7 and doxorubicin (Dox)-treated cells. The oxidation current of NADH was measured via chronoamperometry (CA), and the EC results showed a good linear relationship when compared with NADH quantification using WST-8 assay. The analysis time was only 10 s and limit of detection (LOD) of NADH was 1.78 µM. Our EC method has the potential to replace conventional WST assays for cell viability and cytotoxicity experiments.

• 전기화학회지
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• 제23권3호
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• pp.66-72
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• 2020

본 연구에서는 글루코스 검출을 위한 HRP (horseradish peroxidase)와 GOD (glucose oxidase)를 혼합한 형태의 다중 효소 반응 바이오센서 개발연구를 수행하였다. 바이오센서는 제작 시간 단축을 위하여 전기전착법을 이용하여 제작하였으며, 경제적인 센서 제작을 위하여 SPE (screen printed electrode)를 사용하였다. 다중 효소 바이오센서의 효과를 확인하기 위하여 단일 효소 바이오센서를 제작하여 비교 및 분석하였다. 센서의 특성을 평가하기 위해서 주사전자현미경(scanning electron microscopy, SEM), 순환전위법(cyclic voltammetry, CV), 전기화학적 임피던스 분광법(electrochemical impedance spectroscopy, EIS), 시간대전류법(chronoamperometry, CA), 흐름 주입분석법(flow injection analysis, FIA)를 수행하였다. SEM, CV, EIS의 분석결과로부터 효소가 전극 표면에 고정화가 잘 된 것을 확인하였고, CA로부터 제작된 다중 효소 바이오센서가 단일 효소 바이오센서에 비해 신호성능이 200% 향상된 것을 확인하였다. 이로부터 HRP와 GOD가 서로 촉매적으로 반응한다는 것을 설명할 수 있었다. 또한, FIA의 결과에서 동일한 농도의 글루코스 용액을 4회 나누어 주입하였을 때, 전류신호량이 일정함을 확인하였고, 농도에 따른 전류신호량을 분석하여 신호민감성, 재현성, 안정성 등이 우수함을 설명할 수 있었다.

• Journal of Electrochemical Science and Technology
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• 제15권1호
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• pp.152-160
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• 2024

In this study, ZnCo₂O₄ nanoparticles were synthesized via the coprecipitation method using different annealing temperatures from 200℃ to 800℃. By varying the treatment temperature, the morphology changed from amorphous to tetragonal, and finally to polygonal particles. As temperature increased, the sizes of the nanoparticles also changed from 5 nm at 200℃ to approximately 500 nm at 800℃. The fabricated material was used to modify the working electrode of a screen-printed carbon electrode (SPE), which was subsequently used to survey the detection performance of the antibiotic, chloramphenicol (CAP). The electrochemical results revealed that the material exhibits a good response to CAP. Further, the sample that annealed at 600℃ displayed the best performance, with a linear range of 1-300 μM, and a limit of detection (LOD) of 0.15 μM. The sensor modified with ZnCo₂O₄ also exhibited the potential for utilitarian application when the recovery in a real sample was above 97%.

• 전기화학회지
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• 제10권2호
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• pp.150-154
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• 2007

본 연구에서는 8족 금속 원소인 오스뮴을 중심금속으로 일차아민을 포함하고 있는 피리딘 (pyridine) 화합물을 배위시켜 착화합물을 합성하였다. 합성된 오스뮴 착화합물은 $[Os(dme-bpy)_2(ap-im)Cl]^{+/2+}$을 순환전압전류법을 포함한 다양한 전기화학분석법을 이용하여 전기적인 성질을 조사하였다. 또한 합성된 일차 아민을 갖는 오스뮴 착화합물을 이용하여 당 측정용 바이오센서를 제작하기 위하여 금 나노입자(Cold nano-particles)를 전기적 흡착방법을 이용하여 스크린 인쇄방법으로 만든 탄소반죽 전극 (Screen Printed Carbon Electrodes, SPEs) 위에 고정화를 시켰다. 당과 당 분해효소(Glucose Oxidase, GOx)를 혼합하여 발생하는 산화촉매전류를 확인하였고, 당 농도에 따라 변화하는 산화촉매전류의 양도 확인하였다. 새롭게 만들어진 바이오센서는 1 mM 과 같은 낮은 농도에서 감응할 수 있는 바이오센서에 응용할 수 있음을 확인하였다.

• 전기화학회지
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• 제25권1호
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• pp.13-21
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• 2022

There is an increasing interest in monitoring of specific biomarker for determining progression of a disease or efficacy of a treatment. Conventional method for quantification of specific biomarkers as enzyme linked immunosorbent assay (ELISA) has high material costs, long incubation periods, requires large volume of samples and involves special instruments, which necessitates clinical samples to be sent to a lab. This paper reports on the development of an electrochemical biosensor to measure total immunoglobulin E (IgE), a marker of asthma disease that varies with age, gender, and disease in concentrations from 0.3-1000 ng/mL with consuming 20 µL volume of whole blood sample. The sensor provides rapid, accurate, easy, point-of-care measurement of IgE, also, sequential monitoring of total IgE with ovalbumin (OVA) induced mice is another application of sensor. Taken together, these results provide an alternative way for detection of biomarkers in whole blood with low volumes and long-term ex-vivo assessments for understanding the progression of a disease.

• 전기화학회지
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• 제11권3호
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• pp.176-183
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• 2008

본 연구에서는 8족 금속 원소인 osmium을 중심금속으로 4가지의 착물을 합성하였다. 합성한 착물은 ${[Os(bpy)}_2{(ap-im)Cl]}^{+/2+}$, ${[Os(dme-bpy)}_2{(ap-im)Cl]}^{+/2+}$, ${[Os(dmo-bpy)}_2{(ap-im)Cl]}^{+/2+}$, ${[Os(dcl-bpy)}_2{(ap-im)Cl]}^{+/2+}$이다. 합성된 착물을 순환전압전류법을 포함한 다양한 전기화학분석방법을 이용하여 전기적 성질을 조사하여 작용기에 따른 전위의 변화를 다음의 전위구간에서 $E_p$:$-0.06\;V{\sim}0.313\;V$ vs. Ag/AgCl 확인하였다. 합성한 화합물을 전기적 흡착방법으로 고정된 금나노입자(gold nano-particles)를 전극 위에 자기조립방식으로 고정화를 시켰다. 당과 당 분해효소(Glucose Oxidase, GOx)에 의한 촉매반응의 전류를 확인하였고, glucose농도에 따른 변화하는 전류의 양도 확인하였다. 마지막으로 고정된 4가지의 osmium complex는 서로 다른 전위로 인하여 촉매전류의 양이 달라지는 것을 알 수 있었고, 이로 인해 redox complex의 전위가 촉매반응에 미치는 영향을 확인 할 수 있었다.