DNA tetrahedron-mediated immune-sandwich assay for rapid and sensitive detection of PSA through a microfluidic electrochemical detection system

Dezhi Feng,Xianting Ding,Yi Xu,Xiao Wang,Chenguang Wang,Xianqiang Mi,Jing Su,Tingrui Pan,Guifang He

doi:10.1038/s41378-021-00258-x

Abstract

Prostate-specific antigen (PSA) is the most widely used biomarker for the early diagnosis of prostate cancer. Existing methods for PSA detection are burdened with some limitations and require improvement. Herein, we developed a novel microfluidic–electrochemical (μFEC) detection system for PSA detection. First, we constructed an electrochemical biosensor based on screen-printed electrodes (SPEs) with modification of gold nanoflowers (Au NFs) and DNA tetrahedron structural probes (TSPs), which showed great detection performance. Second, we fabricated microfluidic chips by DNA TSP-Au NF-modified SPEs and a PDMS layer with designed dense meandering microchannels. Finally, the μFEC detection system was achieved based on microfluidic chips integrated with the liquid automatic conveying unit and electrochemical detection platform. The μFEC system we developed acquired great detection performance for PSA detection in PBS solution. For PSA assays in spiked serum samples of the μFEC system, we obtained a linear dynamic range of 1–100 ng/mL with a limit of detection of 0.2 ng/mL and a total reaction time <25 min. Real serum samples of prostate cancer patients presented a strong correlation between the “gold-standard” chemiluminescence assays and the μFEC system. In terms of operation procedure, cost, and reaction time, our method was superior to the current methods for PSA detection and shows great potential for practical clinical application in the future.

Highlights

Prostate cancer is one of the most common malignant tumors in the male population in the world
Wen et al.[26] utilized DNA tetrahedron structural probes (TSPs) to promote the efficient identification of aptamers with cocaine, reducing the detection limit to 33 nM (~10 ng/mL), which was three to four orders of magnitude higher than that of similar works; Chen et al.[27] fabricated an ultrasensitive electrochemical immunosensor for Prostate-specific antigen (PSA) detection using DNA TSPs and acquired a lower detection limit of 1 pg/mL, while the detection based on doublestranded DNA was 50 pg/mL
The electrochemical biosensor was first constructed by screen-printed electrodes (SPEs) modified with Au NFs and DNA TSPs, which achieved a linear dynamic range of 0–100 ng/mL and an limit of detection (LOD) of 2 pg/mL

Summary

Introduction

Prostate cancer is one of the most common malignant tumors in the male population in the world. We developed a novel microfluidic– electrochemical (μFEC) detection system by introducing electrochemical biosensors, DNA TSPs, and microfluidic chips simultaneously for simple, rapid, and sensitive PSA detection. The electrochemical biosensor we constructed was based on a screen-printed electrode modified with gold nanoflowers (Au NFs) with the purpose of increasing the specific surface area and improving the chemical signal response.

Results

Conclusion