Folding Paper-Based Aptasensor Platform Coated with Novel Nanoassemblies for Instant and Highly Sensitive Detection of 17β-Estradiol

• DOI: 10.1021/acssensors.9b01633
• Publication Date: 2019-11-28T09:26:56Z
• Authors: Tao Ming; Yang Wang; Jinping Luo; Juntao Liu; Shuai Sun; Yu Xing; Guihua Xiao; Hongyan Jin; Xinxia Cai
• Keywords: Paper; Base Sequence; Estradiol; Nanotubes, Carbon; Metal Nanoparticles; Biosensing Techniques; Electrochemical Techniques; Aptamers, Nucleotide; Microfluidic Analytical Techniques; 01 natural sciences; 0104 chemical sciences; Methylene Blue; Limit of Detection; Point-of-Care Testing; Lab-On-A-Chip Devices; Humans; Gold; Electrodes

Owing to its critical role in the development of female reproductive tissues and as a clinical biomarker, there is an urgent need to develop a rapid and cost-effective method to sensitively detect 17β-estradiol (E2). In this work, a folding aptasensor platform with microfluidic channels for the label-free electrochemical detection of E2 is described. The platform, designed with a delicate folding structure, integrating filter holes, microfluidic channels, reaction chambers, and a three-electrode system, is extremely easy to use. To increase the detection sensitivity and immobilize the aptamer, we synthesized a novel nanoassembly consisting of amine-functionalized single-walled carbon nanotube/new methylene blue/gold nanoparticles (AuNPs) and modified the working electrode with this nanoassembly. The calibration curve obtained from the experimental results exhibited a linear range between 10 pg mL-1 and 500 ng mL-1 (R2 = 0.993), and a detection limit of 5 pg mL-1 was achieved (S/N = 3). Furthermore, experiments to detect E2 in clinical serum were conducted, and the results were highly similar to those obtained using a large electrochemical luminescence apparatus. By integrating multiple functional components, adopting novel nanoassemblies, and using a folding structure, this paper-based platform not only has great potential as a simple and convenient integrated device for point-of-care testing of E2, but also as a portable, low-cost, and highly sensitive aptasensor platform capable of detecting many diagnostic biomarkers with the appropriate aptamers.