We reported here a new assay to detect base excision repair activities from purified enzymes, as well as in cell-free extracts. The multiplex format rests upon the encoding of magnetic beads with the fluorophore Alexa 488, thanks to a fast and original procedure. Fluorescently encoded microbeads are subsequently functionalized by lesion-containing DNA NanoBeacons labeled with the fluorophore/quencher pair Cyanine 5/BHQ2. Probes cleavage, induced by targeted enzymes leads to Cyanine 5 signal enhancement, which is finally quantified by flow cytometry. The multiplex assay was applied to the detection of restriction enzymes activities as well as base excision repair processes. Each test requires only 500fmol of DNA substrate, which constitutes great sensitivity compared to other BER functional assays. The present biosensor is able to detect both uracil DNA N-glycosylase (UNG) and AP-endonuclease 1 (APE1) within few nanograms of nuclear extract. Additionally, we demonstrated that the corresponding assay has potential application in DNA repair inhibitor search. Finally, the current multiplexed tool shows several advantages in comparison to other functional BER assays with no need of electrophoretic separation, straightforward, easy and reproducible functionalization of encoded microbeads and a high stability of DNA probes in cell-free extracts.
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http://dx.doi.org/10.1016/j.bios.2014.02.040 | DOI Listing |
Anal Chem
January 2025
State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China.
Timely and accurate detection of trace mycotoxins in agricultural products and food is significant for ensuring food safety and public health. Herein, a deep learning-assisted and entropy-driven catalysis (EDC)-Argonaute powered fluorescence single-particle aptasensing platform was developed for ultrasensitive detection of fumonisin B (FB) using single-stranded DNA modified with biotin and red fluorescence-encoded microspheres as a signal probe and streptavidin-conjugated magnetic beads as separation carriers. The binding of aptamer with FB releases the trigger sequence to mediate EDC cycle to produce numerous 5'-phosphorylated output sequences, which can be used as the guide DNA to activate downstream Argonaute (Ago) for cleaving the signal probe, resulting in increased number of fluorescence microspheres remaining in the final reaction supernatant after magnetic separation.
View Article and Find Full Text PDFACS Nano
January 2025
State Key Laboratory of Marine Food Processing and Safety Control, Dalian Polytechnic University, Dalian 116034 Liaoning, China.
ACS Appl Mater Interfaces
January 2025
Fujian Provincial Key Laboratory of Polymer Materials, College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China.
Luminescent metal-organic frameworks (MOFs) with exceptional dynamics and diverse active sites possess tremendous potential in information security and anticounterfeiting applications. However, traditional MOF systems are based on broadband spectral signals with spectrum overlap, which easily leads to low-resolution signal identification, compromising the overall security level. Here, we report the coordination-defect-induced amorphous pure-MOF microsphere with switchable whispering-gallery-mode (WGM) signals as a mode-dependent security platform.
View Article and Find Full Text PDFAnal Chem
January 2025
College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, People's Republic of China.
Nowadays, optical tweezers play a vital role not only in optical manipulation but also in bioassay. As principal optical trapping objects, microbeads can combine optical tweezers with suspension array technology, with amply focused laser beams and adequately concentrated tags contributing to highly sensitive detection. In view of the inefficiency of conventional single-trap optical tweezers, multitrap systems are developed.
View Article and Find Full Text PDFPolymers (Basel)
November 2024
Shandong Key Laboratory of Healthy Food Resources Exploration and Creation, School of Food Science and Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
The development of fluorescent sensors with high sensitivity and fast response times is attracting the interest of more and more researchers. Herein, dual-emission ratiometric molecularly imprinted fluorescent encoded microspheres were fabricated and applied for the fast detection of norfloxacin. Core-shell-structured imprinted polymers with ZIF-8 as the supporting core were obtained first and two quantum dots with green and red emission provided the fluorescent signal.
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