front 1 intro | back 1 fluorescence tech widely used bc of simple operation, high sensitivity, good selectivity, high spatial / temporal resolution |
front 2 PROBLEM | back 2 traditional fluorophores often suffer from aggregation caused quenching (ACQ) at high concentrations or in aggregated state (weakened luminescence) too much emission in dilute solutions, because t strong fluorescence in aqueous soln bc of poor water solubility (since not water soluble, they aggregate which = fluorescence prematurely) |
front 3 new finding | back 3 class compounds - aggregation induced emission (AIE) - bc were opposite in that showed negligible emission in dilute solns, but enhanced fuorescence in aggregate / solid state
since then, AIEgens developed for many things thought process: AIEs seem great!!! RIGHT? like wow discovered a new / better version of what had before (ACQ). are there drawbacks??? SEE NEXT CARD |
front 4 problem with AIEs and what do its problems lead to? | back 4
lead to: therefore -> must explore new environmentally friendly, biocompatible, water-soluble AIEgens |
front 5 = must find new/better way | back 5 no data |
front 6 natural products have AIE properties | back 6 could be solution? |
front 7 what specifically is being studied for its AIE properties??? | back 7
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front 8 what they found abt Jat | back 8
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front 9 real life importance / urgency to develop assay methods for trace miRNA | back 9 miRNA is closely associated w/ diseases. need biomarker detection at low concentration (routine (standard) detection methods are not sensitive enough to detect them) |
front 10 what was made | back 10
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front 11 how the thing made works | back 11
this is reliable and stable. acheives ultrasensitive, label free detection of miRNA by combining EDC, AIEgens, and DNA hydrogels + expands application of water-soluble AIEgens and natural AIEgens |
front 12 experimental section | back 12 no data |
front 13 entropy driven amplification rxn | back 13
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front 14 synthesis of DNA-modified polyacrylamide polymer chains | back 14
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front 15 formation of DNA hydrogen and fluorescence detection | back 15
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front 16 results/discussion | back 16 no data |
front 17 aggregation-induced emission characteristics of Jat | back 17
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front 18 prove hypothesis: _____(place hypothesis here) (i think that its a good AIE???) | back 18 Jat in THF/water mixture was analyzed using dynamic light scattering (DLS)
Jat fluoresence in diff polarities was observed
photoluminescence quantum yields (PLQYs) of dispersed Jat in water, nanosuppression, powder were 0.31% (relative std dev = 5.04%), 1.23% (RSD = 4.72%), and 3.37% (RSD = 4.01%) = suggest Jat was AIE-active further show AIE character: measured emission lifetimes
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front 19 single crystal structure and molec mechanism of AIE | back 19
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front 20 DNA hydrogen fluorescent biosensor for the detection of microRNA | back 20
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front 21 optimization of sensing conditions | back 21 fluorescense emission comes from aggregated Jat in DNA hydrogel, so [Jat] was optimized first
# outputs from entropy signal amp influenced fluorescence intensity a lot
time for formation of DNA hydrogel optimized
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front 22 miRNA assay by DNA hydrogel fluorescent biosensor | back 22 to investiagte sensitivity + quantitative application of biosensor designed, diff conc. of miRNA-21 monitored by proposed biosensor under optimal conditions
LIMIT OF DETECTION (LOD) - ESTIMATED TO BE 0.049 fM FOR MIRNA-21 DETECTION. LOWER THAN PREVIOUS ASSAY METHODS REPORTED RESULT = HIGHLY SENSITIVE MIRNA ASSAY CAN BE REALIZED BY MONITORING CHANGE IN FLUORESCENCE INTENSITY OF SYSTEM fluo biosensor proposed = versatile assay platform -> can detect other targets by changing DNA base sequence of template, outputs, fuels |
front 23 performance evaluation of the system and real sample assay | back 23 antiinterference capability of strategy to detect miRNA-21, used 4 analogs that mixed w/ target (miRNA-21)
stability of assay investigated
show practicability of assay
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front 24 conclusions | back 24
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front 25 stuff i think I should know | back 25 no data |
front 26 what is the analyte? | back 26 microRNA (miRNA). The DNA hydrogel fluorescence biosensor developed in the paper uses miRNA as a catalyst to trigger the entropy-driven circuit, which leads to the aggregation of Jat and the turn-on of fluorescence. Therefore, the biosensor can be used to detect miRNA in a label-free and ultrasensitive manner. this miRNA assay was used to confirm Jat's superior fluorescence biosensing in aqueous solution. miRNA = biomarker |
front 27 what does the paper propose? | back 27 novel DNA hydrogel fluorescence biosensor based on a water-soluble natural AIEgen, jatrorrhizine (Jat), for ultrasensitive and label-free detection of miRNA. potential to be used for early diagnosis + monitoring of diseases |
front 28 Would you describe the device developed in this study as quantitative or qualitative? Why? | back 28 DEVICE is quantitative because it can be used to measure the concentration of miRNA in a sample. ex: The DNA hydrogel fluorescence biosensor has an ultralow limit of detection (0.049 fM, S/N = 3) for miRNA. It also has excellent stability and acceptable reliability for real sample assay. in the study overall, researchers used PAGE (qualitative) to determine if amplification was working used quantitative and qualitative measurements to determine AIE characteristics of Jat (ex: structure, SEM, intensity with diff amounts THF, etc.) |
front 29 what is the device developed? what did it show? | back 29 novel DNA hydrogel fluorescence biosensor based on using Jat for detection of trace miRNA |
front 30 why was a new AIE needed/useful? | back 30 need is that the fluorophore should not emit light in an aqueous solution, even containing DNA and other biomacro- molecules, until the target biomolecules are added. important to explore new environmentally friendly, biocompatible, and water-soluble AIEgens. |
front 31 why is Jat better than other AIEs? what makes it this way? | back 31 it is water soluble and thus does not emit fluorescence in aqueous solution until the formation of DNA hydrogel, this makes it superior in fluorescence biosensing in aqueous solution. This is due to its IM motion and TICT which lead to nonradiative decay. in aggregate, nonradiative decay is restricted = strong fluorescence |
front 32 What's the limitation of biomarker detection methods? What was done to overcome this? | back 32 major challenge that hinders biomarker detection includes: some biomarkers exist at extremely low concentrations, and the routine detection methods are not sensitive enough to detect them. his was solved by successfully incorporating entropy-driven amplification, allowing the proposed device to be ultra sensitive |
front 33 what is jat? whats its role in this study? | back 33 it acts as a fluorescent probe in the proposed device to facilitate detection of miRNA via DNA hydrogel and entrop driven amp |
front 34 why was spiking used? | back 34 miRNA-21 in human serum was detected by using a standard addition method. A series of samples were prepared by adding known concentrations of miRNA-21 to 100-fold-diluted human serum and then the concentrations of miRNA-21 were determined in the spiked samples spiked determine anti interference - determine if analogs to miRNA would affect results all had about 100% recovery ish Seems that since it went well there was no interferences with the complex matrix and the percent recovery values are really high which is good further emphasizes the selectivity of the method. |
front 35 were any blanks used? explain | back 35 yes
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front 36 limit of detection? explain | back 36 limit of detection in this experiment tells lowest concentration or amount of analyte, miRNA, reliably detected by the assay. Says something about how well the assay can detect low concentrations of the analyte |
front 37 standard addition? explain | back 37 To further verify the practicability of the assay system, miRNA-21 in human serum was detected by using a standard addition method. A series of samples were prepared by adding known concentrations of miRNA-21 to 100-fold-diluted human serum and then the concentrations of miRNA-21 were determined in the spiked samples used standard addition to determine if analogs to miRNA-21 would interfere with results |
front 38 how is limit of detection important for this study? | back 38 A lower limit of detection of miRNA was achieved by employing entropy driven amplification, allowing the assay to have a low limit of detection (can detect low concentrations of the analyze, miRNA) |
front 39 why is DNA hydrogel used? | back 39 it restricts IM movement of Jat which = strong fluorescence emission |
front 40 why was HEPES, acrylamide, TEMED added? | back 40 to synthesize the DNA modified polyacrylamide polymer chains |
front 41 what did the assay show overall? | back 41
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front 42 what are the 2 buffers used and why? | back 42 two buffers used: Tris-HCl Buffer in the entropy-driven amplification reaction. Tris-HCl used to obtain substrate for EDC process the HEPES buffer in the formation of the DNA hydrogel and fluorescence detection. |
front 43 what is the limit of detection? | back 43 0.049 fM |
front 44 what does the RDS show? | back 44
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front 45 gold standards used | back 45 miRNA detection EDC and DNA based amplification dynamic light scattering (DLS) to prove that formation of aggregates occurs of Jat in weakly polar solvents |
front 46 what was optimized | back 46 [Jat]
# outputs ffrom EDC bc it influences fluorescence intensity a lot
time for formation of DNA hydrogel optimized
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front 47 studied jat characteristics using and if qualitative or quantitative | back 47
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front 48 higher intensity = | back 48 higher concentration of miRNA |
front 49 controls | back 49 PAGE band 10 - positive control 1-5 negative controls negative control - testing if DNA hydrogel form with everything except output to determine that output is necessary for hydrogel formation |
front 50 assay results | back 50
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front 51 is there a calibration curve? | back 51 yes, for the intensity of the fluorescence using the assay with miRNA |
front 52 where was selectivity shown? | back 52 in using analogs along with the assay to determine anti-interference, which shows good selectivity |
front 53 can the assay be used for other types of detections? | back 53 yes, if DNA base, template, and fuels are changed. |
front 54 stability of assay? | back 54 fluorescence intensity is stable (RSD = 3.72) for about 72 hrs |
front 55 what is an AIEgen? | back 55 aggregation-induced emission luminogen |
front 56 signal amplification strategy? | back 56 EDC, to increase signal and thus decrease the detection limit (detects lower/trace amounts of miRNA) |
front 57 why use genetic material for this assay and DNA amplification? | back 57 bc nucleic acid is a versatile construction material for biosensors bc of its predictability and programmability of watson-crick base pairing |
front 58 2 parts of the biosensing strategy for detection of miRNA | back 58
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front 59 why was THF used? | back 59 is a weakly polar solvent, used to determine Jat's aggregation (emission) in more/less polar solvents to assess its AIE characteristics |
front 60 quantitative limits in the paper | back 60 diff concentrations miRNA-21
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