Fluorine-free synthesis of Ti 3 C 2 MQDs for smartphone-based fluorescent and colorimetric determination of acetylcholinesterase and organophosphorus pesticides

Ti3C2 MQDs were synthesized using an effective fluorine-free method with excitation/emission maxima at 390/490 nm and a fluorescence quantum yield of 11.78%. In contrast to the traditional, hazardous, and time-consuming process of HF pretreatment, our fluorine-free method is safe and simple. Acetylcholinesterase (AChE) could catalyze the hydrolysis of acetylthiocholine (ATCh) to produce thiocholine which was further reacted with Ehrman’s reagent and decomposed to form a yellow product 2-nitro-5-thiobenate anion (TNB). Due to the obvious overlap between the excitation spectrum of Ti3C2 MQDs and the absorption spectrum of TNB, AChE catalyzed the hydrolysis of substrate DTNB/ATCh to form TNB, which can effectively quench the fluorescence of Ti3C2 MQDs through the inner filter effect (IFE).
However, the presence of organophosphorus (OPs) inhibited the activity of AChE, leading to a less expressed IFE and increasing recovery of fluorescence. This was used for the quantification of OPs with a detection limit of 0.20 μg·L-1. Moreover, with the constant increase of AChE activity, the color of the reaction system changed visibly from colorless to yellow, and then from yellow to colorless with further continuous addition of OPs. A colorimetric detection with a paper-based sensor of AChE activity and OP concentration was also fabricated by analyzing changes in RGB value using a smartphone APP. In this work, we proposed an effective fluorescence/colorimetric two-mode detection method, which opened a new horizon to detect other targets.

Near-infrared fluorescent probe for evaluating the acetylcholinesterase effect in the aging process and dietary restriction via fluorescence imaging

Dietary restriction (DR), as a natural intervention, not only benefits the neuroendocrine system, but also has an antiaging action. Acetylcholinesterase (AChE) is one of the most important bioactive substances and plays a major part in choline changes in the aging process. Thus, we aim to evaluate the effect of DR on AChE in the brains of aging animals. In this study, we synthesize a NIR fluorescent probe BD-AChE for the real-time and in situ monitoring of AChE level changes in living cells and living mice, notably in brains.
In situ visualization with BD-AChE verified a decrease in the AchE level in the brains of mice aging models. Evidently, the prepared probe has the excellent capability of measuring AChE variation in the brains of aging mice with DR via NIR fluorescence bioimaging, indicating that long-term DR can effectively affect AChE levels in the brain. The attenuation of AChE level in the brain of aging mice after DR could be helpful in infering the advantageous impact of DR on age-related neurodegenerative disease, as a better treatment alternative in the future.

A new fluorescent probe for sensing of biothiols and screening of acetylcholinesterase inhibitors.

A new N2O-type BODIPY probe (LF-Bop) has been proposed for the selective and sensitive detection of biologically relevant small molecular thiols. This detection is based on the Michael addition reaction between the thiol and nitrostyrene groups in the probe, which decreases the quenching effect from the nitro group, thus resulting in the recovery of the deep-red fluorescence from the BODIPY structure. The results show that LF-Bop is able to detect all tested free thiols through a fluorescence turn-on assay.
The lowest limit of detection (LOD) for glutathione was found to be down to nanomolar levels (220 nM). Based on this probe, we have developed a new fluorescence assay for the screening of acetylcholinesterase inhibitors. In total, 11 natural and synthetic alkaloids have been evaluated. Both experimental measurements and theoretical molecular docking results reveal that both natural berberine and its synthetic derivative dihydroberberine are potential inhibitors of acetylcholinesterase

One-Step Facile Synthesis of Nitrogen-Doped Carbon Dots: A Ratiometric Fluorescent Probe for Evaluation of Acetylcholinesterase Activity and Detection of Organophosphorus Pesticides in Tap Water and Food.

  • Evaluation of acetylcholinesterase (AChE) activity and determination of organophosphorus pesticides (OPs) are of great importance for the clinical diagnosis of several serious diseases correlated with their variations in human blood serum. In this study, a highly selective and sensitive ratiometric fluorescent probe was innovatively fabricated for the evaluation of AChE activity and the determination of OPs in tap water and food on the basis of the inner filter effect (IFE) between nitrogen-doped carbon dots (N-CDs) and 2,3-diaminophenazine (DAP). N-CDs were synthesized via a one-pot hydrothermal method by using pancreatin and 1,2-ethanediamine as precursors. N-CDs showed excellent fluorescence properties and negligible cytotoxicity on human cervical carcinoma HeLa cells and human embryonic kidney 293T cells, suggesting their further biological applications.
  • Upon the addition of AChE and choline oxidase, acetylcholine was catalyzed to produce choline that was further oxidized to produce H2O2. In the presence of horseradish peroxidase, o-phenylenediamine reacted with H2O2 to produce fluorescent DAP. Therefore, a ratiometric fluorescent probing platform existed via IFE between N-CDs with a fluorescence signal at 450 nm and DAP with a fluorescence signal at 574 nm. OPs irreversibly impeded the catalytic activity of AChE, finally leading to the decrease of DAP amount and the variation of ratiometric fluorescent signal.
  • Under optimal conditions, such a fluorescent probe showed relatively low detection limits of 0.38 U/L for AChE, 3.2 ppb for dichlorvos, and 13 ppb for methyl-parathion. Practical application of this ratiometric fluorescent probe to detect OPs was further verified in tap water and food samples with satisfying results that were highly consisted with the results obtained by GC-MS.

Acetylcholinesterase Fluorescent Activity Kit (2 Plate)

K015-F1 Arbor Assays 2x96 well plates 411 EUR

Amplite® Fluorimetric Acetylcholinesterase Assay Kit *Red Fluorescence*

11402 AAT Bioquest 200 Tests 227 EUR

Amplite® Fluorimetric Acetylcholinesterase Assay Kit *Red Fluorescence*

11402-200Tests AAT Bioquest 200 Tests 222 EUR

Amplite® Fluorimetric Acetylcholinesterase Assay Kit *Green Fluorescence*

11401-200Tests AAT Bioquest 200 Tests 222 EUR

Acetylcholinesterase

AP78858 SAB 1mg 2640 EUR

Acetylcholinesterase

AP80050 SAB 1mg 2640 EUR

Acetylcholinesterase

AP80187 SAB 1mg 2640 EUR

Acetylcholinesterase

AP80192 SAB 1mg 2640 EUR

Acetylcholinesterase

AP80202 SAB 1mg 2640 EUR

Acetylcholinesterase (AChE)

018-39 PHOENIX PEPTIDE 100 μg 140.4 EUR

Acetylcholinesterase Reagent

DACEN25ML BioAssay Systems 100 89 EUR

Acetylcholinesterase, NT (ACHE)

MBS6012768-005mg MyBiosource 0.05(mg 745 EUR

Acetylcholinesterase, NT (ACHE)

MBS6012768-5x005mg MyBiosource 5x0.05mg 3195 EUR

Acetylcholinesterase Antibody

E38PA1007 EnoGene 100ul 225 EUR

Acetylcholinesterase, Antibody

GWB-4F28A5 GenWay Biotech 0.1 ml Ask for price

Acetylcholinesterase Antibody

GWB-51EE94 GenWay Biotech 1 ml Ask for price

Acetylcholinesterase, Antibody

GWB-520BDB GenWay Biotech 0.1 mg Ask for price

Acetylcholinesterase Antibody

GWB-7EB934 GenWay Biotech 0.1 ml Ask for price

Acetylcholinesterase Antibody

R35265-100UG NSJ Bioreagents 100 ug 339.15 EUR

Acetylcholinesterase Antibody

MBS9232450-01mL MyBiosource 0.1mL 415 EUR

Acetylcholinesterase Antibody

MBS9232450-5x01mL MyBiosource 5x0.1mL 1841 EUR

Acetylcholinesterase Antibody

MBS8580273-01mL MyBiosource 0.1mL 305 EUR

Acetylcholinesterase Antibody

MBS8580273-01mLAF405L MyBiosource 0.1mL(AF405L) 465 EUR

Acetylcholinesterase Antibody

MBS8580273-01mLAF405S MyBiosource 0.1mL(AF405S) 465 EUR

Acetylcholinesterase Antibody

MBS8580273-01mLAF610 MyBiosource 0.1mL(AF610) 465 EUR

Acetylcholinesterase Antibody

MBS8580273-01mLAF635 MyBiosource 0.1mL(AF635) 465 EUR

Paper-based fluorescent sensor for rapid naked-eye detection of acetylcholinesterase activity and organophosphorus pesticides with high sensitivity and selectivity.

Various strategies have been proposed for the sensing of acetylcholinesterase (AChE) activity and organophosphorus pesticides (OPs). However, the practical application of most methods is restricted by their intrinsic drawbacks such as complexity, long analysis time, and high cost. Thus, it is highly desirable to develop simple, fast and sensitive approaches for AChE activity and OPs detection. Herein, we reported a simple paper-based fluorescent sensor (PFS) based on the aggregation induced emission (AIE) effect of tetraphenylethylene (TPE) and the addition reaction capability of maleimide, which has been used as a powerful tool for rapid naked-eye detection of AChE activity and OPs.
The introduction of TPE provides the probe with unique fluorescence property in solid state and is of great importance for improving the sensitivity of PFS. The hydrolysis product of acetylthiocholine catalyzed by AChE induced the maleimide ring destruction and activated the fluorescence performance of TPE. Given that AChE activity can be specifically inhibited by OPs, the as-proposed PFS can also be utilized for sensitive detection of OPs. Meanwhile, the variation of fluorescence signal can be readily detected by naked eyes, and low detection limits of 2.5mUmL(-1) and 0.5ngmL(-1) for AChE activity and OPs are obtained, respectively. Moreover, it has been successfully applied for AChE activity and OPs detection in diluted human serum samples, showing its great potential to be applied in real samples. Thus, this strategy possesses considerable advantages of simplicity, rapid detection, portability, cost efficiency and visualization.

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top