Low sample volume origami-paper-based graphene-modified aptasensors for label-free electrochemical detection of cancer biomarker-EGFR

Abstract

In this work, an electrochemical paper-based aptasensor was fabricated for label-free and ultrasensitive detection of epidermal growth factor receptor (EGFR) by employing anti-EGFR aptamers as the bio-recognition element. The device used the concept of paper-folding, or origami, to serve as a valve between sample introduction and detection, so reducing sampling volumes and improving operation convenience. Amino-functionalized graphene (NH2-GO)/thionine (THI)/gold particle (AuNP) nanocomposites were used to modify the working electrode not only to generate the electrochemical signals, but also to provide an environment conducive to aptamer immobilization. Electrochemical characterization revealed that the formation of an insulating aptamer–antigen immunocomplex would hinder electron transfer from the sample medium to the working electrode, thus resulting in a lower signal. The experimental results showed that the proposed aptasensor exhibited a linear range from 0.05 to 200 ngmL−1 (R2 = 0.989) and a detection limit of 5 pgmL−1 for EGFR. The analytical reliability of the proposed paper-based aptasensor was further investigated by analyzing serum samples, showing good agreement with the gold-standard enzyme-linked immunosorbent assay.

Enhancing the performance of paper-based electrochemical impedance spectroscopy nanobiosensors: An experimental approach

“…Different from commercial ELISA kits ( Tang and Hewlett, 2010 ), the presented nanobiosensors reached a much better limit of detection, cost less, and can be finished in a much shorter time. In comparison to other biosensors that utilize paper substrates ( Y. Wang et al, 2020 ) or zinc oxide nanostructures-supported EIS ( Perumal et al, 2015 ), the approach presented here combines the benefits of these factors to achieve both high sensitivity and low cost.…”

Paper-Based Screen-Printed Electrodes: A New Generation of Low-Cost Electroanalytical Platforms

“…Taking advantage of how easy it is to fold, stack, or cut the paper, there was a subsequent development of 3D multilayer and origami paper-based devices [ 73 , 93 , 117 , 142 , 143 , 144 , 145 , 146 , 147 , 148 , 149 , 150 , 151 , 152 , 153 , 154 , 155 , 156 ], including integration of electrodes directly on paper. These seem to require more laborious procedures of construction but the use of software for transferring wax and ink designs to paper makes this an easy task, especially useful when more sophisticated operations are enabled: e.g., sampling [ 143 , 157 , 158 ], sample delivery [ 146 , 159 ], or sample treatment [ 93 ].…”

“…These seem to require more laborious procedures of construction but the use of software for transferring wax and ink designs to paper makes this an easy task, especially useful when more sophisticated operations are enabled: e.g., sampling [ 143 , 157 , 158 ], sample delivery [ 146 , 159 ], or sample treatment [ 93 ]. As mentioned before, in many of these devices, the electrodes of the electrochemical cell are printed on different layers of the devices with the aim of improving the contact of the electrodes with the sample or decreasing the size of the device [ 73 , 142 , 144 , 152 , 160 , 161 , 162 , 163 , 164 , 165 , 166 ]. Moreover, vertical microfluidics, in comparison with lateral flow, helps to reduce the consumption or reagents and the loss of sensitivity due to the diffusion of the analyte.…”

Nanomaterial‐Based Electrochemical Sensors: Mechanism, Preparation, and Application in Biomedicine

“…Reproduced under the terms and conditions of the Creative Commons Attribution 4.0 International License. [ 72 ] Copyright 2020, The Authors, published by Springer Nature.…”