Real-time detection of telomerase activity in cancer cells using a label-free electrochemical impedimetric biosensing microchip

Cunci, Lisandro; Vargas, Marina Martinez; Cunci, Roman; Gómez-Moreno, Ramón; Pérez, Iván; Baerga‐Ortiz, Abel; González, Caleb; Cabrera, Carlos R.

doi:10.1039/c4ra09689d

Cited by 18 publications

(22 citation statements)

References 41 publications

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“…The method is simple, but the sensitivity remains to be raised to a higher level. Space-caused electrochemical probes were used to build a small biosensor microchip for real-time detection of telomerase activity in less than 20 minutes by electrochemical impedimetric biosensing 33 . Based on structure-switching DNA with ferrocene (Fc) as an electroactive indicator, space-caused electrochemical assay with a very wide linear response range, excellent stability and reproducibility was developed 34 .…”

Section: Assays For the Detection Of Telomerase Activity Using Isothementioning

confidence: 99%

Advances in the detection of telomerase activity using isothermal amplification

Zhang¹,

Lou²,

Xia³

2017

Theranostics

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Telomerase plays a significantly important role in keeping the telomere length of a chromosome. Telomerase overexpresses in nearly all tumor cells, suggesting that telomerase could be not only a promising biomarker but also a potential therapeutic target for cancers. Therefore, numerous efforts focusing on the detection of telomerase activity have been reported from polymerase chain reaction (PCR)-based telomeric repeat amplification protocol (TRAP) assays to PCR-free assays such as isothermal amplification in recent decade. In this review, we highlight the strategies for the detection of telomerase activity using isothermal amplification and discuss some of the challenges in designing future telomerase assays as well.

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Section: Assays For the Detection Of Telomerase Activity Using Isothementioning

confidence: 99%

Advances in the detection of telomerase activity using isothermal amplification

Zhang¹,

Lou²,

Xia³

2017

Theranostics

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“…However, due to the intrinsic difficulty of this technique, most scientific literature limits its use to the Nyquist representation for the detection of molecules. 21…”

Section: Introductionmentioning

confidence: 99%

Static and Dynamic Measurement of Dopamine Adsorption in Carbon Fiber Microelectrodes Using Electrochemical Impedance Spectroscopy

et al. 2018

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In this study, electrochemical impedance spectroscopy was used for the first time to study the adsorption of dopamine in carbon fiber microelectrodes. In order to show a proof-of-concept, static and dynamic measurements were taken at potentials ranging from -0.4 to 0.8 V versus Ag|AgCl to demonstrate the versatility of this technique to study dopamine without the need of its oxidation. We used electrochemical impedance spectroscopy and single frequency electrochemical impedance to measure different concentrations of dopamine as low as 1 nM. Moreover, the capacitance of the microelectrodes surface was found to decrease due to dopamine adsorption, which is dependent on its concentration. The effect of dissolved oxygen and electrochemical oxidation of the surface in the detection of dopamine was also studied. Nonoxidized and oxidized carbon fiber microelectrodes were prepared and characterized by optical microscopy, scanning electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. Optimum working parameters of the electrodes, such as frequency and voltage, were obtained for better measurement. Electrochemical impedance of dopamine was determined at different concentration, voltages, and frequencies. Finally, dynamic experiments were conducted using a flow cell and single frequency impedance in order to study continuous and real-time measurements of dopamine.

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“…This result is in accordance with that of Cunci et al in which they reported that for the Jurkat nuclear extract, 20 min was enough time to observe a quantitatively different change in label-free impedance measurements. 23 Therefore, using the presented system, 30 min is enough time to make qualitative telomerase detection. Other modification times, 60, 120, and 180 min, showed more differences in Δ R , 3 h being the most accurate modification time for fundamental analysis.…”

Section: Resultsmentioning

confidence: 99%

“…Nuclear cell extraction was performed following an established protocol. 23 Briefly, cells were collected in the exponential phase of growth and washed twice with ice-cold PBS (140 mM NaCl, 2.7 mM KCl, 10 mM NaH 2 PO 4 , and 1.8 mM KH 2 PO 4 ). Then, the pellet was resuspended in buffer A [10 mM HEPES pH 7.9, 1.5 mM MgCl 2 , 10 mM KCl, 1 mM DTT, and 1 mM protein-sparing modified fast (PMSF)], incubated on ice for 10 min, and centrifuged at 1500 rpm for 10 min at 4 °C.…”

Section: Methodsmentioning

confidence: 99%

Label-Free Telomerase Activity Detection via Electrochemical Impedance Spectroscopy

et al. 2019

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In the last decade, researchers have been searching for innovative platforms, methods, and techniques able to address recurring problems with the current cancer detection methods. Early disease detection, fast results, point-of-care sensing, and cost are among the most prevalent issues that need further exploration in this field. Herein, studies are focused on overcoming these problems by developing an electrochemical device able to detect telomerase as a cancer biomarker. Electrochemical platforms and techniques are more appealing for cancer detection, offering lower costs than the established cancer detection methods, high sensitivity inherent to the technique, rapid signal processing, and their capacity of being miniaturized. Therefore, Au interdigital electrodes and electrochemical impedance spectroscopy were used to detect telomerase activity in acute T cell leukemia. Different cancer cell concentrations were evaluated, and a detection limit of 1.9 × 105 cells/mL was obtained. X-ray photoelectron spectroscopy was used to characterize the telomerase substrate (TS) DNA probe self-assembled monolayer on gold electrode surfaces. Atomic force microscopy displayed three-dimensional images of the surface to establish a height difference of 9.0 nm between the bare electrode and TS-modified Au electrodes. The TS probe is rich in guanines, thus forming secondary structures known as G-quadruplex that can be triggered with a fluorescence probe. Confocal microscopy fluorescence images showed the formation of DNA G-quadruplex because of TS elongation by telomerase on the Au electrode surface. Moreover, electrodes exposed to telomerase containing 2′,3′-dideoxyguanosine-5′-triphosphate (ddGTP) did not exhibit high fluorescence, as ddGTP is a telomerase inhibitor, thus making this device suitable for telomerase inhibitors capacity studies. The electrochemical method and Au microchip device may be developed as a biosensor for a point-of-care medical device.

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Real-time detection of telomerase activity in cancer cells using a label-free electrochemical impedimetric biosensing microchip

Cited by 18 publications

References 41 publications

Advances in the detection of telomerase activity using isothermal amplification

Advances in the detection of telomerase activity using isothermal amplification

Static and Dynamic Measurement of Dopamine Adsorption in Carbon Fiber Microelectrodes Using Electrochemical Impedance Spectroscopy

Label-Free Telomerase Activity Detection via Electrochemical Impedance Spectroscopy

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