A Ratiometric Fluorescent Bioprobe Based on Carbon Dots and Acridone Derivate for Signal Amplification Detection Exosomal microRNA

Abstract

Recently, sensitive and selective detection of exosomal microRNAs (miRNAs) has been garnering significant attention, because it is related to many complex diseases, including cancer. Herein, we report a ratiometric fluorescent bioprobe based on DNA-labeled carbon dots (DNA-CDs) and 5,7-dinitro-2-sulfo-acridone (DSA) coupling with the target-catalyzing signal amplification for the detection of exosomal miRNA-21. There was high fluorescence resonance energy transfer (FRET) efficiency between carbon dots (CDs) and DSA when the bioprobe was assembled. However, in the presence of the target, with disassembling of the fluorescent bioprobe, the fluorescence intensities of CDs and DSA were changed simultaneously. Because of the ratio of dual fluorescence intensities, this ratiometric fluorescent bioprobe was able to cancel out environmental fluctuations by calculating emission intensity ratio at two different wavelengths, being robust and stable enough for detection of exosomal miRNA-21. In addition, we displayed that a single miRNA-21 can catalyze the disassembly of multiple CDs with DSA theoretically, yielding significant change in the fluorescence ratio for the detection of miRNA-21. With this signal amplification strategy, the limit of detection was as low as 3.0 fM. Furthermore, because of the introduction of lock nucleic acid to mediate the strand displacement reaction, the selectivity of this strategy was improved remarkably, even against single base mismatch sequence. More importantly, our strategy could monitor the dynamic change of exosomal miRNA-21, which maybe becomes a potential tool to distinguish cancer exosomes and nontumorigenic exosomes. In a short, this ratiometric fluorescence bioprobe possessed high stability, sensitivity and selectivity coupling with ease of operation and cost efficiency, leading to great potential for wide application.

Effect of exosomal miRNA on cancer biology and clinical applications

“…For instance, a ratiometric fluorescent bioprobe based on DNA-labeled carbon dots (DNA-CDs) and 5,7-dinitro-2-sulfo-acridone (DSA) coupling with the target-catalyzing signal amplification for the detection of exosomal miRNA-21. There was high fluorescence resonance energy transfer (FRET) efficiency between carbon dots (CDs) and DSA when the bioprobe was assembled [ 81 ].…”

Multi-Carbon Dots and Aptamer Based Signal Amplification Ratiometric Fluorescence Probe for Protein Tyrosine Kinase 7 Detection

“…However, the fluorescence of b-CDs was not quenched when the probe was used to detect PTK 7. As shown in Figure 3 meanwhile, would be reduced if there was an energy transfer [11,32] . The data in Figure 3(D) indicated that whether the fluorescence quenching behaviour of b-CDs by y-CDs disappeared or not was due to their separation.…”

“…Carbon dots (CDs) are a new kind of fluorescence nanomaterial that have attracted wide attention owing to their excellent properties including good photostability, easy modification, stable chemical properties, favourable biocompatibility and excellent water-solubility [9,10] . CDs have been used to set up biosensors due to their excellent properties for metal ions, micromolecules and protein analysis [11][12][13] . Because of the relatively low concentration of PTK 7 in peripheral circulation, the biosensors for PTK 7 detection need to be equipped with high sensitivity and selectivity.…”

“…The strategy of nucleic acid amplification was also successfully used in the construction of the fluorescence probe for microRNAs [20] . Additionally, in fluorescence sensors, the ratiometric fluorescence measurement can afford simultaneous recordings of two measurable signals at one excitation wavelength [11,21] . This is because one measurable signal plays the role of the interior label, which can thereby overcome the drawback of the ease in which a single fluorescence measurement can be influenced by the detection conditions and probe concentrations [22,23] .…”

Recent Advances in Aflatoxins Detection Based on Nanomaterials

“…The electrochemical biosensor is a sensing platform that evaluates changes in electrical parameters (current, impedance, conductivity, voltage, or potential signal) through biochemical reactions between a biometric element and a target analyte [73]. Simple equipment, high sensitivity and easy miniaturization have always been the key research object of analytical researchers [74,75]. In recent years, electrochemical biosensors combined with nanomaterials have been vigorously developed because they can overcome the shortcomings of poor selectivity and low sensitivity in the original sensor detection methods.…”