종이 기반 전기화학 센서의 연구 동향

서민지 한국전기화학회 2024 한국전기화학회지 Vol.27 No.1

신체에 부착하는 웨어러블(wearable) 센서 및 현장 진단 검사(point-of-care testing)가 용이한센서의 필요성이 부각되면서, 종이를 기반으로 하는 센서들이 활발히 연구되어왔다. 종이는 매우저렴하면서도 가볍고 유연할 뿐만 아니라, 표면에 카본과 같은 전도성 물질 및 왁스와 같은 소수성 물질을 입히기 쉽다. 또한, 종이를 이루는 셀룰로오스 섬유에 의한 모세관 현상으로 외부 힘없이 용액의 흐름을 유도할 수 있어 웨어러블 전기화학 센서의 플랫폼으로 특히 주목받고 있다. 이에 따라, 다양한 분석 물질들을 전기화학적인 방법으로 검출하는 종이 기반 센서들이 활발히 개발되어 왔다. 특히, 분석 물질에 따른 전류 값 이외에도, 전기화학 발광현상(electrochemiluminescence) 혹은 전기 변색 물질(electrochromic material)을 도입하여 시각적으로 데이터를 나타내는 센서들도 보고되어 왔다. 이 논문에서는 종이 기반 전기화학 센서들의 제작법 및 다양한 활용 전략을사례 중심으로 소개하였다. With the increasing demand for wearable sensors that are capable of point-of-care testing, paper-based sensors have been extensively studied. Paper is not only extremely costeffective but also lightweight and flexible, and it is easy to apply conductive materials such as carbon and hydrophobic substances like wax to its surface. Moreover, the capillary action caused by cellulose fibers in paper allows the flow of liquid without help from external forces, making paper a particularly promising platform for wearable electrochemical sensors. Accordingly, paper-based sensors for detecting various analytes through electrochemical methods have been actively developed. Recently, paper-based electrochemical sensors that utilize electrochemiluminescence (ECL) or electrochromic materials for the optical read-out have been reported. This review introduces the basic fabrication methods and various application strategies of paperbased electrochemical sensors.

Electrochemical study for simultaneous detection of procaine hydrochloride and its metabolite in biological samples using a nanostructured strong sensor

Farzaneh Haghighian,Sayed Mehdi Ghoreishi,Abdolmohammad Attaran,Fahimeh Zeraatkar Kashani,Asma Khoobi 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.3

Procaine belongs to a type of medicine that excessive dosage creates cardiac arrest and also several allergenic reactions. Thus, continuous monitoring of the drug and its metabolite is necessary for sustainable health management during treatment. The innovative aspect of nanostructure materials has great importance in the advancement of research on modified sensors. In the present study, the electrocatalytic performance of multi-walled carbon nanotubes modified carbon paste electrode was investigated for the simultaneous analysis of procaine hydrochloride and p-aminobenzoic acid with high accuracy and sensitivity. The nanostructured sensor is characterized by microscopic and electrochemical techniques, such as scanning electron microscopy and electrochemical impedance spectroscopy using [Fe(CN)6]3−/4− as the redox probes. The modified sensor shows an improved voltammetric peak current than the unmodified carbon paste electrode. The electrochemical behavior of the modified sensor was studied by cyclic voltammetry and differential pulse voltammetry. The sensor kinetic parameters containing electron transfer rate constant (ks=0.47 s−1) and charge transfer coefficient (α=0.23) were calculated using cyclic voltammetry. The differential pulse voltammetry technique was also investigated in terms of linearity, lower limit of detection, lower limit of quantitation, accuracy and precision, which indicate acceptable results. Under optimized experimental conditions, the concentration linear range for procaine and PABA was obtained in the range of 2.4 to 100.0 µM. The limit of detection values (S/N=3) were calculated to be 62.0 and 49.0 nM for detection of procaine and p-aminobenzoic acid, respectively. Also, the effects of interfering materials, repeatability and stability of the modified sensor were studied. Finally, the proposed sensor was applied for simultaneous and sensitive detection of p-aminobenzoic acid and procaine in real media such as plasma and pharmaceutical products with satisfactory results.

Electrochemical Non-Enzymatic Glucose Sensor based on Hexagonal Boron Nitride with Metal-Organic Framework Composite

( Suresh Ranganethan ),( Sang-mae Lee ),( Jaewon Lee ),( Seung-cheol Chang ) 한국센서학회 2017 센서학회지 Vol.26 No.6

In this study, an amperometric non-enzymatic glucose sensor was developed on the surface of a glassy carbon electrode by simply drop-casting the synthesized homogeneous suspension of hexagonal boron nitride (h-BN) nanosheets with a copper metal-organic framework (Cu-MOF) composite. Comprehensive analytical methods, including field-emission scanning electron microscopy (FE-SEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), cyclic voltammetry, electrochemical impedance spectroscopy, and amperometry, were used to investigate the surface and electrochemical characteristics of the h-BN-Cu-MOF composite. The FE-SEM, FT-IR, and XRD results showed that the h-BN-Cu-MOF composite was formed successfully and exhibited a good porous structure. The electrochemical results showed a sensor sensitivity of 18.1 μAμM^-1cm^-2 with a dynamic linearity range of 10-900 μM glucose and a detection limit of 5.5 μM glucose with a rapid turnaround time (less than 2 min). Additionally, the developed sensor exhibited satisfactory anti-interference ability against dopamine, ascorbic acid, uric acid, urea, and nitrate, and thus, can be applied to the design and development of non-enzymatic glucose sensors.

Bio-Composite Materials Precursor to Chitosan in the Development of Electrochemical Sensors: A Critical Overview of Its use with Micro-Pollutants and Heavy Metals Detection

( Sarikokba Diwakar Tiwari ),( Shailesh Kumar Prasad ),( Dong Jin Kim ),( Suk Soon Choi ),( Seung-mok Lee ) 한국공업화학회 2020 공업화학 Vol.31 No.3

The role of nano bio-composites precursor to chitosan are innumerable and are known for having different applications in various branches of physical sciences. The application to the sensor development is relatively new, where only few literature works are available to address the specific and critical analysis of nanocomposites in the subject area. The bio-composites are potential and having greater affinity towards the heavy metals and several micro-pollutants hence, perhaps are having wider implications in the low or even trace level detection of the pollutants. The nano-composites could show good selectivity and suitability for the detection of the pollutants as they are found in the complex matrix. However, the greater challenges are associated using the bio-composites, since the biomaterials are prone to be oxidized or reduced at an applied potential and found to be a hinderance for the detection of target pollutants. In addition, the materials could proceed with a series of electrochemical reactions, which could produce different by-products in analytical applications, resulting in several complex phenomena in electrochemical processes. Therefore, this review addresses critically various aspects of an evaluation of nano bio-composite materials in the electrochemical detection of heavy metals and micro-pollutants from aqueous solutions.

소규모 대기오염물질 배출사업장 연속 모니터링을 위한 전기화학식 가스센서의 온·습도 영향과 농도보정 연구

이춘상,김경찬,최다영,김주연,주흥수,한진석 한국냄새환경학회 2023 실내환경 및 냄새 학회지 Vol.22 No.4

In this study, the performances of H2S, NH3, and HCl sensors for real-time monitoring in small emission facilities (4, 5 grades in Korea) were evaluated at high concentration conditions of those gases. And the proper approach for the collection of reliable measurement data by sensors was suggested through finding out the effect on sensor performances according to changes in temperature and humidity (relative humidity, RH) settings. In addition, an assessment on sensor data correction considering the effects produced by environmental settings was conducted. The effects were tested in four different conditions of temperature and humidity. The sensor performances (reproducibility, precision, lower detection limit (LDL), and linearity) were good for all three sensors. The intercept (ADC0) values for all three sensors were good for the changes of temperature and humidity conditions. The variation in the slope value of the NH3 sensor showed the highest value, and this was followed by the HCl, H2S sensors. The results of this study can be helpful for data collection by enabling the more reliable and precise measurements of concentrations measured by sensors.

An electrochemical sensor based on [Ru(bpy)2dpp]2+/SMWCNTs/Au modified glassy carbon electrode for the detection of 5ʹ‑GMP

Yu Ying,Huan Siqi,Wang Xiaodan,Yang Cong,Liu Dengyong 한국응용생명화학회 2022 Applied Biological Chemistry (Appl Biol Chem) Vol.65 No.4

A sensitive electrochemical sensor for the selective detection of 5ʹ-guanylic acid (5ʹ-GMP) was prepared by combining sulfonated-multiwalled carbon nanotubes (SMWCNTs) and [Ru(bpy)2dpp]Cl2, which were dripped on the surface of a glass carbon electrode (GCE) immobilized with gold nanoparticles. The 5ʹ-GMP electrochemical biosensor was fabricated using [Ru(bpy)2dpp]2+/SMWCNTs/Au/GCE as working, Ag/AgCl as reference and Pt as auxiliary electrode connected by an electrochemical workstation. The modified electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results showed the sensor’s response current had the best peak shape and maximum peak when the pH of electrolyte was 3, scan speed of CV was in the range of 100 to 180 mV/s, and the enrichment time was in the range of 200 to 300 s. Under the optimum conditions, a linear analytical curve was obtained for 5ʹ-GMP concentrations in the range of 0.01 to 0.5 mmol L− 1, with a detection limit of 0.0014 mmol L− 1. The analytical results of the 5ʹ-GMP sensor were exhibited good consistent with the data from liquid chromatography. The sensor has good reproducibility, long-term stability and strong immunity to interference, and may be a powerful device for 5ʹ-GMP detection, with great advantages such as simple preparation and operation, low equipment cost.

Pt/CNT 전극 기반 전기화학식 센서의 전해질에 따른 황화수소 감지 특성

하윤태,정대웅,권진범,최수지,백수빈 한국센서학회 2023 센서학회지 Vol.32 No.3

With the recent development of industrial technology, the problem of odor due to leakage of toxic gas discharged from industrial complexes is gradually increasing. Among them, hydrogen sulfide is a colorless representative odorous substance that can cause pain through irritation of the mucous membranes of the eyes and respiratory tract, and is a gas that can cause central nervous system paralysis and suffocation when exposed to high concentrations. Therefore, in order to improve the odor problem, research on a gas sensor capable of quickly and reliably detecting a leak of hydrogen sulfide is being actively conducted. A lot of research has been done on the existing metal oxide-based hydrogen sulfide gas sensor, but it has the disadvantage of requiring low selectivity and high temperature operating conditions. Therefore, in this study, a Pt/CNT-based electrochemical hydrogen sulfide gas sensor capable of detecting at low temperatures with high selectivity for hydrogen sulfide was developed. A working electrode capable of selectively detecting only hydrogen sulfide was fabricated by synthesizing Pt nanoparticles as a catalyst on functionalized CNT and applied to an electrochemical hydrogen sulfide gas sensor. It was confirmed that the manufactured Pt/CNT-based electrochemical hydrogen sulfide gas sensor has a current change of up to 100uA for hydrogen sulfide, and the both response time and recovery time were within 15 seconds.

Portable Amperometric Glucose Detection based on NiS/CuS Nanorods Integrated with a Smartphone Device

Heyu Zhao,Kaige Qu,Haoyong Yin,Ling Wang,Yifan Zheng,Shumin Zhao,Shengji Wu The Korean Electrochemical Society 2023 Journal of electrochemical science and technology Vol.14 No.3

Glucose detection is particularly important for clinical diagnosis and personal prevention and control. Herein, the smartphone-based amperometric glucose sensors were constructed using the NiS/CuS nanorods (NRs) as sensing electrodes. The NiS/CuS NRs were prepared through a facile hydrothermal process accompanied by the subsequent vulcanization treatment. The morphological and structural properties of NiS/CuS NRs were characterized with SEM, EDS, XRD, and XPS. Electrochemical measurements including cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy display that NiS/CuS NRs can act as highly efficient electrocatalyst for glucose detection. The NiS/CuS NRs electrodes present a wide detection range of 1-8000 µM for glucose sensing with the sensitivity of 956.38 µA·mM^-1·cm^-2. The detection limit was 0.35 µM (S/N=3). When employed in smartphone-based glucose sensing device, they also display a high sensitivity of 738.09 µA·mM^-1·cm^-2 and low detection limit of 1.67 µM. Moreover, the smartphone-based glucose sensing device also presents favorable feasibility in determination of glucose in serum samples with the recoveries ranging between 99.5 and 105.8%. The results may provide a promising viewpoint to design other new portable glucose sensors.

3D 프린팅을 이용한 Pt/Carbon Nanotube composite 기반전기화학식 황화수소 가스 센서 제작

하윤태,권진범,최수지,정대웅 한국센서학회 2023 센서학회지 Vol.32 No.5

Among various types of harmful gases, hydrogen sulfide is a strong toxic gas that is mainly generated during spillageand wastewater treatment at industrial sites. Hydrogen sulfide can irritate the conjunctiva even at low concentrations of lessthan 10 ppm, cause coughing, paralysis of smell and respiratory failure at a concentration of 100 ppm, and coma and permanentbrain loss at concentrations above 1000 ppm. Therefore, rapid detection of hydrogen sulfide among harmful gasesis extremely important for our safety, health, and comfortable living environment. Most hydrogen sulfide gas sensors thathave been reported are electrical resistive metal oxide-based semiconductor gas sensors that are easy to manufacture andmass-produce and have the advantage of high sensitivity; however, they have low gas selectivity. In contrast, the electrochemicalsensor measures the concentration of hydrogen sulfide using an electrochemical reaction between hydrogen sulfide,an electrode, and an electrolyte. Electrochemical sensors have various advantages, including sensitivity, selectivity, fastresponse time, and the ability to measure room temperature. However, most electrochemical hydrogen sulfide gas sensorsdepend on imports. Although domestic technologies and products exist, more research is required on their long-term stabilityand reliability. Therefore, this study includes the processes from electrode material synthesis to sensor fabrication and characteristicevaluation, and introduces the sensor structure design and material selection to improve the sensitivity and selectivityof the sensor. A sensor case was fabricated using a 3D printer, and an Ag reference electrode, and a Pt counterelectrode were deposited and applied to a Polytetrafluoroethylene (PTFE) filter using PVD. The working electrode was alsodeposited on a PTFE filter using vacuum filtration, and an electrochemical hydrogen sulfide gas sensor capable of measuringconcentrations as low as 0.6 ppm was developed.

전기화학식 암모니아 가스센서의 측정환경에 따른 특성 연구

오정은,신재용,이상열,강두수,김갑식,천호상 한국냄새환경학회 2021 실내환경 및 냄새 학회지 Vol.20 No.4

The electrochemical type gas sensor has the advantage of being easy to use due its small size, and it is also relatively inexpensive. However, its output can easily vary depending on temperature and humidity conditions. Therefore, it is important to ascertain the exact output characteristics of a sensor according to the measuring environment in order to improve measurement accuracy for any set of given conditions. The purpose of this study is to obtain basic information about the output characteristics of a sensor that is used both indoor and outdoor according to the variation in temperature and humidity conditions in order to improve the accuracy of the sensor. To achieve this result, a calibration curve was made using ammonia standard gas and the calibration factor was calculated using the calibration curve and the measuring accuracy was confirmed with regard to the ammonia sensor. Based on the test results, the variation of the sensor output value was large in relation to temperature and humidity variation. It was found that the output value from the sensor at higher temperature and humidity conditions was also higher. However, the measuring accuracy of the sensor could be improved by more than 10% by applying the calibration factor and an average accuracy of more than 97% could be achieved. It is anticipated that the result of this study can be used as basic data to obtain more accurate results using electrochemical sensors for a given set of temperature and humidity conditions, and therefore, it can also be considered that the reliability and applicability of electrochemical sensors can be improved.