AFM and impedance spectroscopy characterization of the immobilization of antibodies on indium–tin oxide electrode through self-assembled monolayer of epoxysilane and their capture of Escherichia coli O157:H7

Yang, Liju; Li, Yanbin

doi:10.1016/j.bios.2004.06.024

Cited by 201 publications

(63 citation statements)

References 30 publications

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“…The experiment was carried out in a 5 mM Fe(CNÞ Oxidation peaks appear around 0.3 V, which is in accordance with published information [38,39]. GOPTS-functionalized ITO presents lower intensity current than non-functionalized ITO electrodes, which indicates that the organic layer of epoxysilane compounds acts as an insulator between the Fe(CNÞ [18,26]. An increase in electron transfer resistance can be observed in the low-frequency range for organosilane-functionalized substrates with respect to bare substrates.…”

Section: Cyclic Voltammetry and Electrochemical Impedance Spectroscopysupporting

confidence: 84%

“…The same authors presented a study on the AFM and impedance spectroscopy characterization of the specific recognition of E. coli O157:H7 cells by the immobilized anti-E. coli antibodies [18]. They observed a systematic increase in the impedance spectra on GOPTS-functionalized substrates, anti-E. coli antibodies immobilization and biorecognized E. coli O157:H7 with respect to bare ITO substrates.…”

Section: Introductionmentioning

confidence: 95%

“…Such conducting organic polymers have been found to have extensive sensing applications [22][23][24]. The intermediate molecule used to functionalize ITO substrates in the present work is (3-glycidoxypropyl)trimethoxysilane (GOPTS), and its use has been widely reported in the literature [18,25,26]. This molecule helps controlling ITO physical and chemical properties for biosensing purposes.…”

Section: Introductionmentioning

confidence: 99%

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Organosilane-functionalization of nanostructured indium tin oxide films

et al. 2016

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Fabrication and organosilane-functionalization and characterization of nanostructured ITO electrodes are reported. Nanostructured ITO electrodes were obtained by electron beam evaporation, and a subsequent annealing treatment was selectively performed to modify their crystalline state. An increase in geometrical surface area in comparison with thin-film electrodes area was observed by atomic force microscopy, implying higher electroactive surface area for nanostructured ITO electrodes and thus higher detection levels. To investigate the increase in detectability, chemical organosilane-functionalization of nanostructured ITO electrodes was performed. The formation of 3-glycidoxypropyltrimethoxysilane (GOPTS) layers was detected by X-ray photoelectron spectroscopy. As an indirect method to confirm the presence of organosilane molecules on the ITO substrates, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) were also carried out. Cyclic voltammograms of functionalized ITO electrodes presented lower reduction-oxidation peak currents compared with non-functionalized ITO electrodes. These results demonstrate the presence of the epoxysilane coating on the ITO surface. EIS showed that organosilane-functionalized electrodes present higher polarization resistance, acting as an electronic barrier for the electron transfer between the conductive solution and the ITO electrode. The results of these electrochemical measurements, together with the significant difference in the X-ray spectra between bare ITO and organosilane-functionalized ITO substrates, may point to a new exploitable oxide-based nanostructured material for biosensing applications. As a first step towards sensing, rapid functionalization of such substrates and their application to electrochemical analysis is tested in this work. Interestingly, oxide-based materials are highly integrable with the silicon chip technology, which would permit the easy adaptation of such sensors into lab-on-a-chip configurations, providing benefits such as reduced size and weight to facilitate on-chip integration, and leading to low-cost mass production of microanalysis systems.

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Section: Cyclic Voltammetry and Electrochemical Impedance Spectroscopysupporting

confidence: 84%

Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

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Organosilane-functionalization of nanostructured indium tin oxide films

et al. 2016

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“…[34][35] Impedance detection involves measuring the change in impedance caused by the binding of analytes to receptors (antibodies, DNA, proteins, etc.) immobilized on the surface of electrodes, 36 change in the conductivity of the medium caused by the growth of bacteria, 37 bacterial cells captured on an electrode surface using dielectrophoresis, 38 and change in the ionic concentration of a medium caused by activity of enzyme used as labels. 39 Calorimetric biosensors are based on measuring the heat of a biochemical reaction at the sensing element.…”

Section: Transducer Elementmentioning

confidence: 99%

Development and Applications of Portable Biosensors

2015

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The significance of microfluidics-based and microelectromechanical systems-based biosensors has been widely acknowledged, and many reviews have explored their potential applications in clinical diagnostics, personalized medicine, global health, drug discovery, food safety, and forensics. Because health care costs are increasing, there is an increasing need to remotely monitor the health condition of patients by point-of-care-testing. The demand for biosensors for detection of biological warfare agents has increased, and research is focused on ways of producing small portable devices that would allow fast, accurate, and on-site detection. In the past decade, the demand for rapid and accurate on-site detection of plant disease diagnosis has increased due to emerging pathogens with resistance to pesticides, increased human mobility, and regulations limiting the application of toxic chemicals to prevent spread of diseases. The portability of biosensors for onsite diagnosis is limited due to various issues, including sample preparation techniques, fluid-handling techniques, the limited lifetime of biological reagents, device packaging, integrating electronics for data collection/analysis, and the requirement of external accessories and power. Many microfluidic, electronic, and biological design strategies, such as handling liquids in biosensors without pumps/valves, the application of droplet-based microfluidics, paper-based microfluidic devices, and wireless networking capabilities for data transmission, are being explored.

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“…ITO is an opto-electronic material of high optical transparency and electrical conductivity. Recent research has shown that ITO also possesses excellent biocompatibility for cellular and biomolecular studies due to its stability under physiological conditions [14] [15]. Silanes have been successfully used in the past to modify ITO [16].…”

Section: Introductionmentioning

confidence: 99%

Electrically-Assisted Formation and Desorption of Dodecyl Phosphate Self-Assembled Monolayers on Indium Tin Oxide Surfaces

Tang¹,

Antoni²,

Schönbächler

et al. 2006

ECS Trans.

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Molecularly homogenous and hydrophobic surfaces play an important role in a number of technological applications such as tribology and protein/cellular adhesion. Self-assembled monolayers of dodecyl phosphates (DDPO 4 ) have previously been demonstrated to spontaneously form on titanium oxide, producing surfaces with excellent hydrophobic properties. In this paper, we report on the adsorption of DDPO 4 onto a transparent electronic material, indium tin oxide (ITO), under both open circuit and applied potential conditions. We have used two complementary surface characterization techniques: variable angle scanning ellipsometry and contact angle measurements to investigate the adsorption of DDPO 4 on an ITO surface. Under open circuit condition, both methods consistently confirmed the formation of DDPO 4 monolayers on the ITO surface. The presence of an electrical field increased the amount of DDPO 4 adsorbed on the ITO surface. An applied anodic electrical stimulus of 1800 mV resulted in an exponential loss of the monolayer as confirmed by X-ray photoelectron spectroscopy and electrochemical optical waveguide lightmode spectroscopy (EC-OWLS). This electrically stimulated selective adsorption/desorption of DDPO 4 opens up new ways to tailor the physico-chemical properties of surfaces.

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AFM and impedance spectroscopy characterization of the immobilization of antibodies on indium–tin oxide electrode through self-assembled monolayer of epoxysilane and their capture of Escherichia coli O157:H7

Cited by 201 publications

References 30 publications

Organosilane-functionalization of nanostructured indium tin oxide films

Organosilane-functionalization of nanostructured indium tin oxide films

Development and Applications of Portable Biosensors

Electrically-Assisted Formation and Desorption of Dodecyl Phosphate Self-Assembled Monolayers on Indium Tin Oxide Surfaces

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