Abstract:A novel double-hairpin DNA inducing a dual circuit catalyzed hairpin assembly (DC-CHA) strategy was proposed to fabricate electrochemiluminescence (ECL) biosensors for multiple target (microRNA-21 and microRNA-155) ultrasensitive detection.
“…Currently, nucleic acid amplification technologies have become a powerful and popular tool for signal amplification. Additionally, the widely used nucleic acid amplification strategies include catalytic hairpin assembly (CHA), , rolling circle amplification (RCA), hybridization chain reaction (HCR), loop-mediated isothermal amplification (LAMP), polymerase chain reaction (PCR), strand displacement amplification (SDA), and so on. Among them, CHA as a constant temperature, enzyme-free, and low-cost amplification strategy , has achieved signal amplification through hairpin structure self-assembly and strand displacement reaction, which has attracted special attention.…”
Here,
a target-induced three-dimensional DNA network structure
(T-3D Net) produced by catalytic hairpin assembly (CHA) was proposed
as a novel signal amplifier to fabricate an ultrasensitive electrochemiluminescence
(ECL) biosensor for microRNAs detection. Usually, conventional CHA
can produce only one output DNA in each target cycle, while the proposed
strategy could produce multiple output DNA by using DNA-functionalized
magnetic beads (MBs) and gold nanoparticles (AuNPs) to form T-3D Net.
Then, the T-3D Net with high loading capacity could be completely
collapsed by dissolving AuNPs to efficiently convert trace microRNA-21
into a large amount of output DNA. Furthermore, the nanocomposite
containing Ru(bpy)3
2+ as luminophore and boron
nitride quantum dots (BNQDs) as coreactant provided a strong initial
ECL response owing to the short electron transfer distance between
luminophore and coreactant (signal-on). Next, the DNA duplex probes
labeled with N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and dopamine (DA) (S1-ABEI/S2-DA) were further
immobilized on the nanocomposite to reduce the background signal due
to the double quenching effect of DA for both ABEI and Ru(bpy)3
2+ (signal-off). In the presence of the output
DNA with enzyme-assisted self-recycling, S2-DA was displaced and detached
from the electrode surface to achieve ECL signal recovery. Simultaneously,
S1-ABEI restored a stable hairpin structure, making ABEI close to
the electrode surface for more effective resonance energy transfer
(RET) between ABEI and Ru(bpy)3
2+, which greatly
improved the final ECL response (signal-super on). Thus, the ECL biosensor
demonstrated superior performance for ultrasensitive detection of
microRNA-21 with low detection limit (0.33 aM) and was successfully
applied to monitor the expression of microRNA-21 in human cancer cell
lysates. This strategy provided an ultrasensitive way for the detection
of biomolecules and revealed an effective avenue for diseases diagnosis.
“…Currently, nucleic acid amplification technologies have become a powerful and popular tool for signal amplification. Additionally, the widely used nucleic acid amplification strategies include catalytic hairpin assembly (CHA), , rolling circle amplification (RCA), hybridization chain reaction (HCR), loop-mediated isothermal amplification (LAMP), polymerase chain reaction (PCR), strand displacement amplification (SDA), and so on. Among them, CHA as a constant temperature, enzyme-free, and low-cost amplification strategy , has achieved signal amplification through hairpin structure self-assembly and strand displacement reaction, which has attracted special attention.…”
Here,
a target-induced three-dimensional DNA network structure
(T-3D Net) produced by catalytic hairpin assembly (CHA) was proposed
as a novel signal amplifier to fabricate an ultrasensitive electrochemiluminescence
(ECL) biosensor for microRNAs detection. Usually, conventional CHA
can produce only one output DNA in each target cycle, while the proposed
strategy could produce multiple output DNA by using DNA-functionalized
magnetic beads (MBs) and gold nanoparticles (AuNPs) to form T-3D Net.
Then, the T-3D Net with high loading capacity could be completely
collapsed by dissolving AuNPs to efficiently convert trace microRNA-21
into a large amount of output DNA. Furthermore, the nanocomposite
containing Ru(bpy)3
2+ as luminophore and boron
nitride quantum dots (BNQDs) as coreactant provided a strong initial
ECL response owing to the short electron transfer distance between
luminophore and coreactant (signal-on). Next, the DNA duplex probes
labeled with N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and dopamine (DA) (S1-ABEI/S2-DA) were further
immobilized on the nanocomposite to reduce the background signal due
to the double quenching effect of DA for both ABEI and Ru(bpy)3
2+ (signal-off). In the presence of the output
DNA with enzyme-assisted self-recycling, S2-DA was displaced and detached
from the electrode surface to achieve ECL signal recovery. Simultaneously,
S1-ABEI restored a stable hairpin structure, making ABEI close to
the electrode surface for more effective resonance energy transfer
(RET) between ABEI and Ru(bpy)3
2+, which greatly
improved the final ECL response (signal-super on). Thus, the ECL biosensor
demonstrated superior performance for ultrasensitive detection of
microRNA-21 with low detection limit (0.33 aM) and was successfully
applied to monitor the expression of microRNA-21 in human cancer cell
lysates. This strategy provided an ultrasensitive way for the detection
of biomolecules and revealed an effective avenue for diseases diagnosis.
“…Consequently, the conversion of an excited state into the ground state (i.e., from unstable to stable) leads to the emission of light. Accordingly, the formation of the free radicals in ECL occurs, which are segregated into the co-reaction and quenching pathways [184][185][186]. ECL sensing techniques exhibit excellent features including high sensitivity, rapid speed of response and easy operational procedures.…”
Due to the proliferative cancer rates, cardiovascular diseases, neurodegenerative disorders, autoimmune diseases and a plethora of infections across the globe, it is essential to introduce strategies that can rapidly and specifically detect the ultralow concentrations of relevant biomarkers, pathogens, toxins and pharmaceuticals in biological matrices. Considering these pathophysiologies, various research works have become necessary to fabricate biosensors for their early diagnosis and treatment, using nanomaterials like quantum dots (QDs). These nanomaterials effectively ameliorate the sensor performance with respect to their reproducibility, selectivity as well as sensitivity. In particular, graphene quantum dots (GQDs), which are ideally graphene fragments of nanometer size, constitute discrete features such as acting as attractive fluorophores and excellent electro-catalysts owing to their photo-stability, water-solubility, biocompatibility, non-toxicity and lucrativeness that make them favorable candidates for a wide range of novel biomedical applications. Herein, we reviewed about 300 biomedical studies reported over the last five years which entail the state of art as well as some pioneering ideas with respect to the prominent role of GQDs, especially in the development of optical, electrochemical and photoelectrochemical biosensors. Additionally, we outline the ideal properties of GQDs, their eclectic methods of synthesis, and the general principle behind several biosensing techniques.
“…5b). A novel double-hairpin DNA inducing dual circuit CHA strategy was also proposed for multiple targets ultrasensitive detection coupling with electrochemiluminescence biosensor [63] (Fig. 5c).Fig.…”
Over the decades, the biological role of microRNAs (miRNAs) in the post-transcriptional regulation of gene expression has been discovered in many cancer types, thus initiating the tremendous expectation of their application as biomarkers in the diagnosis, prognosis, and treatment of cancer. Hence, the development of efficient miRNA detection methods
in vitro
is in high demand. Extensive efforts have been made based on the intrinsic properties of miRNAs, such as low expression levels, high sequence homology, and short length, to develop novel
in vitro
miRNA detection methods with high accuracy, low cost, practicality, and multiplexity at point-of-care settings. In this review, we mainly summarized the newly developed
in vitro
miRNA detection methods classified by three key elements, including biological recognition elements, additional micro-/nano-materials and signal transduction/readout elements, their current challenges and further applications are also discussed.
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