Label-free protein recognition using an aptamer-based impedance measurement assay

Cai, Hong; Lee, Thomas M. H.; Hsing, I‐Ming

doi:10.1016/j.snb.2005.06.017

Cited by 173 publications

(124 citation statements)

References 31 publications

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“…This effect has been used to rationalize changes in R ct upon binding of a charged target for SAMs [113], for DNA sensors [114,115], and for protein sensors [116][117][118]. Note that surface charge is also dependent on pH, temperature, and other factors.…”

Section: What Causes An Impedance Change?mentioning

confidence: 99%

“…Cai et al reported a thrombin sensor using an aptamer probe on a microfabricated gold electrode [117].They noted increases in R ct and hypothesize that thrombin acts as a hydrophobic insulator (however, it is positively charged and the redox species is negatively charged). Using three replicates, they reported no nonspecific binding of hemoglobin or BSA and a detection limit of 3.6 ng/mL.…”

Section: Faradaic Studiesmentioning

confidence: 99%

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Label‐Free Impedance Biosensors: Opportunities and Challenges

2007

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Impedance biosensors are a class of electrical biosensors that show promise for point-of-care and other applications due to low cost, ease of miniaturization, and label-free operation. Unlabeled DNA and protein targets can be detected by monitoring changes in surface impedance when a target molecule binds to an immobilized probe. The affinity capture step leads to challenges shared by all label-free affinity biosensors; these challenges are discussed along with others unique to impedance readout. Various possible mechanisms for impedance change upon target binding are discussed. We critically summarize accomplishments of past label-free impedance biosensors and identify areas for future research.

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Section: What Causes An Impedance Change?mentioning

confidence: 99%

Section: Faradaic Studiesmentioning

confidence: 99%

Label‐Free Impedance Biosensors: Opportunities and Challenges

2007

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“…4-, resulting in a decrease in the peak current and a broadening of ΔEp. 26,27 The calibration curve obtained as a function of the myoglobin concentration is shown in Fig. 4(C).…”

Section: Electrochemical Detection Of Myoglobinmentioning

confidence: 99%

An Electrochemical Biosensor Based on a Myoglobin-specific Binding Peptide for Early Diagnosis of Acute Myocardial Infarction

et al. 2015

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“…In addition, electrical signals can be directly interfaced with most measurement equipment while other signal modalities may require a transducer to convert the signal [12][13][14][15] . Electrical sensors commonly measure changes in impedance 16,17 , capacitance 18 , or redox activity 19 . However, new challenges are presented as these systems are miniaturized.…”

Section: Introductionmentioning

confidence: 99%

A Microfluidic-based Electrochemical Biochip for Label-free DNA Hybridization Analysis

Ben‐Yoav

Dykstra

Gordonov

et al. 2014

JoVE

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Miniaturization of analytical benchtop procedures into the micro-scale provides significant advantages in regards to reaction time, cost, and integration of pre-processing steps. Utilizing these devices towards the analysis of DNA hybridization events is important because it offers a technology for real time assessment of biomarkers at the point-of-care for various diseases. However, when the device footprint decreases the dominance of various physical phenomena increases. These phenomena influence the fabrication precision and operation reliability of the device. Therefore, there is a great need to accurately fabricate and operate these devices in a reproducible manner in order to improve the overall performance. Here, we describe the protocols and the methods used for the fabrication and the operation of a microfluidic-based electrochemical biochip for accurate analysis of DNA hybridization events. The biochip is composed of two parts: a microfluidic chip with three parallel micro-channels made of polydimethylsiloxane (PDMS), and a 3 x 3 arrayed electrochemical micro-chip. The DNA hybridization events are detected using electrochemical impedance spectroscopy (EIS) analysis. The EIS analysis enables monitoring variations of the properties of the electrochemical system that are dominant at these length scales. With the ability to monitor changes of both charge transfer and diffusional resistance with the biosensor, we demonstrate the selectivity to complementary ssDNA targets, a calculated detection limit of 3.8 nM, and a 13% cross-reactivity with other non-complementary ssDNA following 20 min of incubation. This methodology can improve the performance of miniaturized devices by elucidating on the behavior of diffusion at the micro-scale regime and by enabling the study of DNA hybridization events. Video LinkThe video component of this article can be found at

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Label-free protein recognition using an aptamer-based impedance measurement assay

Cited by 173 publications

References 31 publications

Label‐Free Impedance Biosensors: Opportunities and Challenges

Label‐Free Impedance Biosensors: Opportunities and Challenges

An Electrochemical Biosensor Based on a Myoglobin-specific Binding Peptide for Early Diagnosis of Acute Myocardial Infarction

A Microfluidic-based Electrochemical Biochip for Label-free DNA Hybridization Analysis

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