Hybridization chain reaction-based aptameric system for the highly selective and sensitive detection of protein

Abstract

We introduce here a novel assay for the detection of platelet-derived growth factor BB (PDGF-BB) via hybridization chain reaction (HCR) based on an aptameric system, where stable DNA monomers assemble only upon exposure to a target PDGF-BB aptamer. In this process, two complementary stable species of biotinylated DNA hairpins coexist in solution until the introduction of initiator aptamer strands triggers a cascade of hybridization events that yields nicked double helices analogous to alternating copolymers. In detail, the aptamer firstly opens the hairpins in the solution, creating long concatemers, and then reacts with the antibody captured PDGF-BB on the well surface. Moreover, several experimental conditions including different PDGF-BB aptamers, the spacer length of the selected aptamer and hairpin, etc. are investigated and optimized. Our results show that the coupling of HCR to aptamer triggers for the amplification detection of PDGF-BB achieves a better performance in the fluorescence detection of PDGF-BB as compared to the traditional antibody-antigen-aptamer assays. Upon modification, the approach presented herein could be extended to detect other types of targets. We believe such advancements will represent a significant step towards improved diagnostics and more personalized medical treatment and environmental monitoring.

Highly sensitive homogeneous electrochemical aptasensor for antibiotic residues detection based on dual recycling amplification strategy

“…AMP aptamer sequences (in red), 10 successive adenine bases (in brown) used to reduce any possible steric hindrance effect (Song et al 2012b), the primer recognition fragment (in skyblue) caged in the stem of HP, and extend-DNA (in black). HP has overhanging termini with 6-nt extension at its both ends that can facilitate the polymerization catalyzed by KF polymerase and prohibit the cleavage by T7 exonuclease .…”

DNA for Non-nucleic Acid Sensing

“…The idea remains the design of a nucleotide sequence comprising an aptamer portion (capture) and an input portion that triggers construction of a supramolecular DNA structure (DNA detection/ amplification). This principle has been successfully implemented using the CHA (Zheng et al 2012a), EDC (Cheng et al 2014a, b;Li et al 2013), and HCR Zhang et al 2013;Zhao et al 2013b;Song et al 2012;Yuan et al 2013) strategies.…”

Signal Amplification for Highly Sensitive Immunosensing

“…18 Schematic illustration of the nanoRCA strategy method showed satisfactory results for linear detection range over 5 orders of magnitude for CEA with a detection limit of 1.2 fg mL -1 . HCR has been coupled with the optical-based immunosensors, including fluorescent [76,77], electrochemiluminescence [78], and bioluminescence [79] for signal amplification by loading large amounts of reporting molecules. For example, Song et al [76] introduced streptavidin QDs (SA-QD) as reporting molecules for the detection of PDGF-BB via HCR based on an aptameric system.…”

“…HCR has been coupled with the optical-based immunosensors, including fluorescent [76,77], electrochemiluminescence [78], and bioluminescence [79] for signal amplification by loading large amounts of reporting molecules. For example, Song et al [76] introduced streptavidin QDs (SA-QD) as reporting molecules for the detection of PDGF-BB via HCR based on an aptameric system. Wang et al [80] designed a label-free fluorescence aptasensing strategy using target-triggered HCR amplification and the superior fluorescence quenching ability of GO to the fluorescence of SYBR Green I (SG) as an indicator absorbed to ssDNA (Fig.…”