Engineering a Rolling-Circle Strand Displacement Amplification Mediated Label-Free Ultrasensitive Electrochemical Biosensing Platform

Abstract

In this work, an original rolling-circle strand displacement amplification (RC-SDA) was developed by introducing a circle DNA with two recognition domains as a template instead of the limited liner DNA template in traditional strand displacement amplification (SDA), which displayed much shorter reaction time down to 30 min and quite higher conversion efficiency of more than 1.77 × 10 8 compared with those of traditional strand displacement amplification (SDA) and could be applied to construct a label-free biosensor for ultrasensitive detection of an HIV DNA fragment. Once the target HIV DNA fragment interacts with the template circle DNA, the RC-SDA could be activated to dramatically output amounts of mimic target DNA with the assistance of the Phi29 DNA polymerase and Nb.BbvCI enzyme. In application, while the output products were captured by the DNA tetrahedral nanoprobe (DTNP) modified electrode, the electrochemical tag silver nanoclusters (AgNCs) on DTNP would be released from the electrode surface, accompanied with an obviously decreased electrochemical signal. This way, the developed signaloff biosensor was successfully applied to realize the rapid and ultrasensitive detection of target HIV DNA fragment with a detection limit down to 0.21 fM, which exploits the new generation of a universal strategy beyond the traditional ones for applications in biosensing assay, clinic diagnosis, and DNA nanobiotechnology.

Enhanced Electrochemiluminescence of Graphitic Carbon Nitride by Adjustment of Carbon Vacancy for Supersensitive Detection of MicroRNA

“…Firstly, the bare GCE should be burnished with 0.3 and 0.05 μm of alumina powder by the literature method . Secondly, 10 μL of 1 mg/mL Au NPs@V C -g-C 3 N 4 was dropped onto the fresh GCE and dried.…”

Materialistic Interfaces with Nucleic Acids: Principles and Their Impact

“…Yuan et al developed a series of guest materials with electrochemical and electroluminescent characteristics and the integration of nucleic acids skills, contributing to the measurements of miRNA, proteins, bio‐molecules, and metal ions. The nucleic acids skills contained HCR, [ 161 ] DNAzyme, [ 162 ] circle rolling amplification, [ 163 ] catalytic hairpin assembly (CHA), [ 164 ] and strand displacement amplification (SDA). [ 165 ]…”

Nucleic acid isothermal amplification-based soft nanoarchitectonics as an emerging electrochemical biosensing platform

“…This was dropped onto the DNA tetrahedron modified electrode, which replaced DNA–AgNCs via the toehold strand displacement reaction leading to a dramatic decrease in electrochemical signal response resulting in an ultra-low detection limit down to 0.1 fM. 21 These two examples of different nanoarchitectonic strategies show very high signal-amplification efficiency. Moreover, RCA could be combined with other efficient amplification technologies, such as clustered regularly interspaced short palindromic repeats (CRISPR)/Cas to construct a “signal-on” immobilization-free electrochemical biosensing platform for micro RNA21.…”