Label-free detection of telomerase activity in HeLa cells using electrochemical impedance spectroscopy

Abstract

A simple assay based on electrochemical impedance spectroscopy (EIS) for detection of telomerase activity is developed, and it is demonstrated that the label-free EIS method is capable of detecting the telomerase activity in HeLa cells with a detection limit of 1000 HeLa cells without using any amplification technique.

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

“…37 °C which is the temperature selected for the biosensor microchip used in this study. Telomerase biosensors previously reported in the literature 18,24 were placed inside an incubator or thermal cycler, depending on the experimental conditions assayed. Either, promoting the lengthening of a probe on a surface or the Telomeric Repeat Amplification Protocol (TRAP) assay 34 , this later step was unavoidable before measurement and, in turn, for telomerase activity detection.…”

“…Using this principle, many electrochemical telomerase biosensors have been reported using differential pulse voltammetry, 16,17,18,19 electroluminescence, 20,21 and chronocoulometry, 22,23 with only one that uses electrochemical impedance spectroscopy (EIS) for a dual purpose: for surface characterization and as the biosensor signal transducer. 24 …”

Sensitive Electrochemical Detection of Telomerase Activity Using Spherical Nucleic Acids Gold Nanoparticles Triggered Mimic-Hybridization Chain Reaction Enzyme-Free Dual Signal Amplification

“…Electrochemical technology is becoming more recognized in analyzing telomerase activity due to its own merits of high sensitivity, simplified set-up, low cost. [27][28][29] To further enhance the detection sensitivity, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 4 approaches for background decrease or signal amplification are commonly considered. Enzyme exonuclease III has been employed to decrease background signal, 30,31 but protein enzyme has its own shortcomings of making the detection relatively costly and complicated.…”

Analysis of telomerase activity based on a spired DNA tetrahedron TS primer

“…The detection limit was calculated to be lower than 10 HeLa cells (43 standard deviations (SDs)), and the dynamic range covered 4 orders of magnitude (0-50,000 cells). The sensitivity of STTS sensor is at least 2 magnitudes lower than other surface extension-based electrochemical telomerase sensors without amplification (Pavlov et al, 2004;Shao et al, 2008;Yang et al, 2011;Kim et al, 2013), and even comparable with to those strategies combined complex amplification to the surface primer strategies (Zheng et al, 2008;.…”

“…Fortunately, electrochemical biosensors, with their advantages of low cost , high-sensitivity, and high compatibility with other technologies (Liu et al, , 2012, offer us great opportunities for advanced telomerase assays (Pavlov et al, 2004;Yang et al, 2011). Recently, a series of electrochemical telomerase biosensors (ETBs) have been developed based on G-rich tetraplex DNA binder (Sato et al, 2005), bio-barcode method , alkaline phosphatase label (Pavlov et al, 2004) and guanine oxidation signals (Eskiocak et al, 2007) etc.…”