High sensitive ratiometric fluorescence analysis of trypsin and dithiothreitol based on WS2 QDs

Duan, Xinhe; Li, Ning; Wang, Guannan; Su, Xingguang

doi:10.1016/j.talanta.2020.121171

Cited by 21 publications

(8 citation statements)

References 32 publications

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“…Figure 5b plots the R with the trypsin concentration, and the results agree on a linear relation with the trypsin concentration, and the fitting curve is Y = −0.42•logC-1.46 (R 2 = 0.99). The lowest detectable concentration of trypsin arrives at 0.1 pM, which is higher than many reported sensors [8,28,29].…”

Section: Determination Of Trypsin In Serummentioning

confidence: 57%

Ultrasensitive detection of trypsin in serum via nanochannel device

et al. 2021

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A highly sensitive trypsin sensing system in serum was developed by using an anodic alumina oxide (AAO)-based, trypsin substrate-decorated hybrid ion permeation membrane. Owing to the trypsin-triggered peptide hydrolyzation reaction, the surface electrical feature of the peptide-decorated hybrid ion membrane changed. The electric double layer effect reduces the effective ion current diameter in the AAO nano unit, so that the ion current rectification ratio will be enhanced, realizing the quantitative detection of trypsin. The lowest detection concentration can be achieved as low as 0.1 pM. This method is no need for sample prepreparation, easy to operate, highly sensitive, and also applicable to other enzyme evaluation systems by changing corresponding substrates. This study provides a new idea for selective measurements of proteases in complex biological samples.

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Section: Determination Of Trypsin In Serummentioning

confidence: 57%

Ultrasensitive detection of trypsin in serum via nanochannel device

et al. 2021

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“…Based on the Cy5s-Ab-Flu-Aza fluorescence intensity profiles, the ratiometric curve was obtained as the ratio between the green and red signals (Figure , right axis). The half-life (τ 1/2 ) of drug release obtained from both intensity-based and ratiometric profiles, fitted by a second-order exponential function, is about the same, in the order of τ 1/2 ∼ 4.0 ± 0.5 h. Compared to the brightness profiles, the ratiometric curve can be utilized to calculate the drug release degree independently of the sample and instrumental setup. − …”

Section: Resultsmentioning

confidence: 95%

“…Targeted drug delivery (TDD) systems, consisting of a drug or prodrug bound to a target-specific carrier such as an antibody, − peptide, − nanoparticle, − or extracellular matrix compounds, facilitate drug delivery, minimize side effects to normal cells and organs, and thereby help to improve the safety of treatment in clinics. , TDD systems additionally equipped with a switchable fluorescent dye (SD) bound to the drug or prodrug through a cleavable linker (Figure a) provide real-time monitoring of drug distribution and accumulation, as well as detection and diagnosis of abnormal cells. , Upon the environment-mediated cleavage of the linker, the switchable dye becomes fluorescent or changes its emission wavelength, signaling the drug release. The fluorescence signal from the dye is, however, affected by the light absorption and scattering in the biological sample, in particular, in the body, and is also dependent on the instrumental setup. , The dual-signal ratiometric fluorescence measurements utilizing a second, nonswitchable reference dye (RD, Figure b) provide internal calibration which eliminates these undesirable factors and improves the detection sensitivity and quantification. − …”

Section: Introductionmentioning

confidence: 99%

Ratiometric Fluorescence Monitoring of Antibody-Guided Drug Delivery to Cancer Cells

et al. 2021

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Ratiometric measurements utilizing two independent fluorescence signals from a dual-dye molecular system help to improve the detection sensitivity and quantification of many analytical, bioanalytical, and pharmaceutical assays, including drug delivery monitoring. Nevertheless, these dual-dye conjugates have never been utilized for ratiometric monitoring of antibody (Ab)guided targeted drug delivery (TDD). Here, we report for the first time on the new, dual-dye TDD system, Cy5s-Ab-Flu-Aza, comprising the switchable fluorescein-based dye (Flu) linked to the anticancer drug azatoxin (Aza), reference pentamethine cyanine dye (Cy5s), and Her2-specific humanized monoclonal Trastuzumab (Herceptin) antibody. The ability of ratiometric fluorescence monitoring of drug release was demonstrated with this model system in vitro in the example of the human breast cancer SKBR3 cell line overexpressing Her2 receptors. The proposed approach for designing ratiometric, antibody-guided TDD systems, where a "drug−switchable dye" conjugate and a reference dye are independently linked to an antibody, can be expanded to other drugs, dyes, and antibodies. Replacement of the green-emitting dye Flu, which was found not detectable in vivo, with a longer-wavelength (red or near-IR) switchable fluorophore should enable quantification of drug release in the body.

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“…Recently, many efforts have been reported regarding trypsin determination. Several biosensors based on fluorescent, electrochemical, and colorimetric methods have been developed to detect trypsin [15,26,60,61]. Fluorescence-based homogeneous assays are the most popular ones for trypsin activity monitoring due to their simple processes, high sensitivity, and convenient operation.…”

Section: Sprectophtometric Assay Of Protease Activitymentioning

confidence: 99%

Detection of Sub-Nanomolar Concentration of Trypsin by Thickness-Shear Mode Acoustic Biosensor and Spectrophotometry

et al. 2021

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The determination of protease activity is very important for disease diagnosis, drug development, and quality and safety assurance for dairy products. Therefore, the development of low-cost and sensitive methods for assessing protease activity is crucial. We report two approaches for monitoring protease activity: in a volume and at surface, via colorimetric and acoustic wave-based biosensors operated in the thickness-shear mode (TSM), respectively. The TSM sensor was based on a β-casein substrate immobilized on a piezoelectric quartz crystal transducer. After an enzymatic reaction with trypsin, it cleaved the surface-bound β-casein, which increased the resonant frequency of the crystal. The limit of detection (LOD) was 0.48 ± 0.08 nM. A label-free colorimetric assay for trypsin detection has also been performed using β-casein and 6-mercaptohexanol (MCH) functionalized gold nanoparticles (AuNPs/MCH-β-casein). Due to the trypsin cleavage of β-casein, the gold nanoparticles lost shelter, and MCH increased the attractive force between the modified AuNPs. Consequently, AuNPs aggregated, and the red shift of the absorption spectra was observed. Spectrophotometric assay enabled an LOD of 0.42 ± 0.03 nM. The Michaelis–Menten constant, KM, for reverse enzyme reaction has also been estimated by both methods. This value for the colorimetric assay (0.56 ± 0.10 nM) is lower in comparison with those for the TSM sensor (0.92 ± 0.44 nM). This is likely due to the better access of the trypsin to the β-casein substrate at the surface of AuNPs in comparison with those at the TSM transducer.

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High sensitive ratiometric fluorescence analysis of trypsin and dithiothreitol based on WS2 QDs

Cited by 21 publications

References 32 publications

Ultrasensitive detection of trypsin in serum via nanochannel device

Ultrasensitive detection of trypsin in serum via nanochannel device

Ratiometric Fluorescence Monitoring of Antibody-Guided Drug Delivery to Cancer Cells

Detection of Sub-Nanomolar Concentration of Trypsin by Thickness-Shear Mode Acoustic Biosensor and Spectrophotometry

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