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Updated: Feb 11, 2026

Hollow Microneedle-based Sensor for Multiplexed Transdermal Electrochemical Sensing
Published on: June 1, 2012
A fires novel report of exosomal electrochemical sensor for sensing micro RNAs by using multi covalent attachment p19
Elham Ghazizadeh1, Zahra Naseri1, Mahmoud Reza Jaafari2
1Department of Medical Biotechnology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
Abstract:
Exosomes are natural spherical phospholipids vesicles derived from cells. Dropping MCF-7 exosome (with high biomarkers as exosomal case) covalently onto the SCPE-GNP causes the sensor to be stable due to the electrochemical induction of positive charges of different biomarkers with [Fe(CN)6] -3/-4 reactions. In the following, the covalent p19 connection with the biomarkers of exosome turns off the sensor. After adding the hybrid of miR21-probe, its tight coupling to p19 has reestablished the system. As a result, this sensor has been able to detect miR21 with high sensitivity and specificity. For the first time, the exosomal electrochemical properties were proven as the electrochemical amplifier bed. The limit of detection (LOD) was 1 a.M. due to the existence of various biomarkers for connecting covalent to p19. Electrochemical impedance (EIS) and differential pulse voltammetry (DPV) are used for miR sensing on the MCF-7 exosome-p19 composite. Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS) and Ultraviolet Visible (UV) spectroscopic techniques are used to understand the interactions between each layer. These vesicles can be used as a natural source for biocompatible devices that are used in transfection using an electrochemical method at a cost-effective and high-performance basis.
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