Upconversion Fluorescent Aptasensor for Polychlorinated Biphenyls Detection Based on Nicking Endonuclease and Hybridization Chain Reaction Dual-Amplification Strategy

Abstract

A novel upconversion fluorescent aptasensor based on hybridization chain reaction and nicking endonuclease has been developed for detection of polychlorinated biphenyls (PCBs). It combined the dual advantages of UCNPs and HCR. Two harpins (H1 and H2) were first designed according to the partial complementary sequence (cDNA) of the PCB72/106. Since the aptamer specifically recognized the target, the cDNA was detached from the magnetic microspheres (MMPs). The cDNA could initiate hybridization chain reaction (HCR) and open the stems of H1 and H2. After the addition of nicking endonuclease, UCNPs were further away from the quenchers (BHQ-1). Hence, the fluorescence intensity of upconversion nanoparticals (UCNPs) could be restored via fluorescence resonance energy transfer (FRET). Therefore, the fluorescence of UCNPs was directly proportional to concentration of PCB72/106, which was the basis for the quantification of PCB72/106. PCB72/106 could be analyzed within the ranges of 0.004 to 800 ng/mL with a detection limit of 0.0035 ng/mL ( S/ N = 3). The aptasensor was also used for the detection of water and soil samples, and the average recoveries ranged from 93.4% to 109.7% and 83.2% to 118.5%, respectively. The relative standard deviations (RSDs) were all below 3.2%. The signal was first amplified through HCR and further amplified with the help of nicking endonuclease. This work also provided the opportunity to develop fluorescent aptasensors for other targets using this dual-amplification strategy.

Advances in Optical Sensors for Persistent Organic Pollutant Environmental Monitoring

“…The concentrations provided by the proposed method were in great accordance with those obtained by means of the analytical techniques such as gas chromatography and mass spectrometry. Wang et al [ 83 ] introduced the use of upconversion nanoparticles (UCNPs), a new class of imaging agents that showed long lifetime, absence of autofluorescence, high photo-stability and low toxicity. The principle of the fluorescent aptasensor for PCB was based on the dual-amplification strategy using nicking endonuclease and hybridization chain reaction (HCR).…”

“…Then, the addition of PCB and the binding with the aptamer induced the aggregation of AuNPS and changed the color of the solution from red to blue. ( b ) Representation of the fluorescent aptasensor for PCB detection with the development of a dual amplification strategy [ 83 ].…”

Construction of DNA Biosensors for Mercury (II) Ion Detection Based on Enzyme-Driven Signal Amplification Strategy

“…Because they only cut one strand of DNA, the other strand of DNA can be retained for signal amplification. This nickase-assisted amplification strategy has been developed for the detection of different targets including Hg 2+ [57][58][59][60]. Depending on their recognition sequence, there are many different types of nickase such as Nt.AlWI [61], Nt.BstNBI [62], Nb.BbvC [63] and so on.…”

Construction of a Homogeneous Enzyme-Free Autocatalytic Nucleic Acid Machinery for High-Performance Intracellular Imaging of MicroRNA

“…16 Furthermore, HCR has been extended with improved amplification by integrating additional DNAzymes [17][18][19] or enzymes. [20][21][22] Upon the introduction of analyte, the coupled HCR-DNAzyme machinery is motivated to autonomously assemble dsDNA nanowires carrying numerous DNAzyme units that produce significant readout signal. However, most of the current HCR systems are still limited to the conventional linear polymerization of DNA hairpins, with significant challenges remaining for fabricating nonlinear HCR systems.…”