Aluminum phosphide (AlP) is the main component of rice tablets (a pesticide), which produces phosphine gas (PH3) when exposed to stomach acid. The most important symptoms of PH3 toxicity include, lethargy, tachycardia, hypotension, and cardiac shock. It was shown that Iodine can chemically react with PH3, and the purpose of this study is to investigate the protective effects of Lugol solution in poisoning with rice tablets.
View Article and Find Full Text PDFPharmaceutical cocrystals ( ; Food and Drug Administration, 2018) are crystalline solids produced through supramolecular chemistry to modulate the physicochemical properties of active pharmaceutical ingredients (APIs). Despite their extensive development in interdisciplinary sciences, this is a pioneering study on the efficacy of pharmaceutical cocrystals in wound healing and scar reducing. Curcumin-pyrogallol cocrystal (CUR-PYR) was accordingly cherry-picked since its superior physicochemical properties adequately compensate for limitative drawbacks of curcumin (CUR).
View Article and Find Full Text PDFWith the unpredictable risks on human health and ecological safety, tobramycin (TOB) as an extensively applied antibiotic has embraced global concern. Herein, a label-free fluorescent aptasensor was developed that opened up an innovative sensing strategy for monitoring trace TOB levels. Based on the rolling circle amplification (RCA) process, a giant DNA building was established by the catalytic action of T4 DNA ligase and Phi 29 DNA polymerase with the cooperation of the specific aptamer as a primer skeleton.
View Article and Find Full Text PDFHerein, a facile fluorescent CRISPR-Cas12a-based sensing strategy is presented for prostate specific antigen (PSA), as a prostate cancer biomarker, with the assistance of a cruciform DNA nanostructure and PicoGreen (PG) as a fluorochrome. Highly sensitive recognition of PSA is one of the virtues of the proposed method which comes from the use of unique features of both CRISPR-Cas12a and DNA structure in the design of the aptasensor. The presence of PSA creates a cruciform DNA nanostructure in the sample which can be loaded by PG and make sharp fluorescence emission.
View Article and Find Full Text PDFCocaine is one of the mainly used illegal drugs in the world. Using the signal amplification elements of terminal deoxynucleotidyl transferase (TdT) and CRISPR-Cas12a, a highly sensitive and simple electrochemical aptasensor was introduced for cocaine quantification. When, no cocaine existed in the sample, the 3'-end of complementary strand of aptamer (CS) was extended by TdT, leading to the activation of CRISPR-Cas12a and remaining of very short oligonucleotides on the working electrode.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
February 2022
In this research, a facile fluorescence aptasensor was designed for the ultrasensitive determination of ethanolamine (ETA) as an aliphatic amino alcohol molecule with harmful side effects for human health. Zeolitic imidazolate framework-8 (ZIF-8) as an efficient metal-organic framework was applied to quench the fluorescence emission of the FAM-labeled ETA aptamer. The presence of ETA could recover the fluorescence response under the optimal experimental conditions.
View Article and Find Full Text PDFHerein, a novel targeted delivery system was developed for intracellular co-delivery of doxorubicin (DOX) as a chemotherapeutic drug, antimiR-21 as an oncogenic antagomiR. In this system, DOX was loaded into mesoporous silica nanoparticles (MSNs) and chitosan was applied to cover the surface of MSNs. AS1411 aptamer as targeting nucleolin and antimiR-21 were electrostatically attached onto the surface of the chitosan-coated MSNs and formed the final nanocomplex (AACS nanocomplex).
View Article and Find Full Text PDFColorimetric approaches have received noticeable attention among sensing methods in view of simplicity and watching the color change of sample by the naked eyes. However, developing colorimetric sensing methods which show high sensitivity is still problematic. Herein, based on CRISPR-Cas12a, rolling circle amplification (RCA) and catalytic activity of gold nanoparticles (AuNPs), a colorimetric aptasensor was introduced for highly sensitive detection of aflatoxin M (AFM).
View Article and Find Full Text PDFHerein, an aptasensor is presented for electrochemical determination of ochratoxin A (OTA) based on nontarget-triggered production of rolling circular amplification (RCA). The surface of gold electrode is modified with thiolated complementary strand of aptamer (CS) as both capture probe and primer and OTA aptamer (Apt) as both sensing molecule and padlock probe (PLP). Following the addition of OTA, Apt/OTA conjugate is formed and detached from the electrode surface.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
February 2021
Not only intoxications of aflatoxins are significant risk for human beings, but also; the contamination with these toxins affect the economy. Therefore, developing a rapid, precise and inexpensive determination method is vitally important. Here, a colorimetric aptasensor is introduced for the detection of aflatoxin M (AFM) based on the preservation of gold nanoparticles (AuNPs) against NaCl-induced aggregation by detaching of complementary strand of aptamer (CS) from the aptamer-modified streptavidin coated silica nanoparticles (SNPs) following the addition of target.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
February 2021
Misuse of antibiotics in animal husbandry and presence of their residues in animal foods is a serious crisis worldwide and thus, monitoring the level of them in food samples is vital for human health. Herein, a fluorescent aptasensor was developed for highly sensitive quantification of oxytetracycline (OTC) in food samples. This method is based on OTC aptamer conjugated to magnetic beads, functioned as recognition element, complementary strand of OTC aptamer, and PicoGreen (PG) as a sensitive double-stranded DNA (dsDNA) fluorescent dye.
View Article and Find Full Text PDFIn this study, a fluorescent aptasensor is described for ultrasensitive detection of prostate-specific antigen (PSA) using DNA triangular prism as a platform for attachment of fluorophore (PicoGreen, PG), streptavidin magnetic beads (SMBs) and RecJf exonuclease as enhancers of fluorescence difference between presence and absence of target. Presence of PSA leads to the formation of the DNA origami. So, a strong fluorescence is observed following the addition of PG.
View Article and Find Full Text PDFThis study demonstrated a chemotherapy drug-free delivery system for breast cancer treatment based on a simple DNA nanostructure composed of sequence 1 containing ATP and AS1411 aptamers and sequence 2 containing antimiR-21. The DNA nanostructure was used for co-delivery of KLA peptide and antimiR-21 as antiapoptotic agents. These therapeutic agents could not be internalised into eukaryotic cells freely which is one of the great features of this targeting platform.
View Article and Find Full Text PDFThis study develops a novel electrochemical sensing platform for microcystin-LR (MC-LR) detection. This aptasensor comprises the hybridization of double aptamer to its complementary strand (CS) on the surface of electrode and generation of an Infinity-shaped DNA structure in the absence of target by terminal deoxynucleotidyl transferase (TdT). The formation of Infinity-shaped construction leads to the development of an ultrasensitive aptasensor for MC-LR detection.
View Article and Find Full Text PDFIn this study, a sensor is described for determination of patulin by using ratiometric fluorescence measurement and strand displacement strategy. In the presence of patulin, the ratiometric fluorescence response decreases, owing to disassembly of DNA duplex structure and target-mediated release of TAMRA-labeled complementary DNA sequence2 (cDNA2). While, in the absence of target, the fluorescence resonance energy transfer (FRET) phenomenon happens between FAM and TAMRA under excitation at 490 nm, resulting in the enhancement of ratiometric signal.
View Article and Find Full Text PDFStudies have shown that microRNAs affect the development of tumors. In many cases, they can be applied as biomarkers for the diagnosis of cancer; therefore, simple and sensitive analytical methods for detection of miRNAs are necessary. In this study, miR-141, which is used to diagnose several types of cancer, was detected in water and serum samples using a biosensor designed based on streptavidin-coated magnetic beads (SMBs), complementary sequences of miR-141 and PicoGreen as the fluorescent dye.
View Article and Find Full Text PDFHerein, a simple electrochemical sensor is proposed for 17β-estradiol (E2) determination. In this sensing platform, split DNA aptamers for E2 were applied as recognizing agents. In the presence of E2, split aptamers are bound to E2 and establish split1-E2-split2 complex as a bridge on the surface of electrode.
View Article and Find Full Text PDFHerein, an electrochemical aptasensor is described for detection of ampicillin (Ampi). The sensing strategy is based on the application of a ladder-shaped DNA structure as a multi-layer physical block on the surface of gold electrode. Attributing to the electrostatic repulsion and physical prevention of the ladder-shaped DNA structure, ultrasensitive detection of Ampi was achieved with a detection limit as low as 1 pM.
View Article and Find Full Text PDFThis study describes a novel electrochemical aptasensor for detection of α-synuclein (α-syn) oligomer, an important biomarker related to Parkinson's and Alzheimer's diseases. The sensing platform is based on exonuclease I (Exo I), terminal deoxynucleotidyl transferase (TdT) and methylene blue. The aptasensor exploits the improved sensitivity because of applications of TdT and Exo I and also a label-free aptamer (Apt).
View Article and Find Full Text PDFObjectives: Here, a novel cruciform DNA nanostructure was developed for targeted delivery of doxorubicin (Dox), as an anticancer agent, to lung (A549 cells) and breast (4T1 cells) cancer cells. The cruciform DNA nanostructure consisted of AS1411 aptamer as targeting agent and Forkhead Box Protein M1(FOXM1) aptamer as therapeutic agent.
Methods: MTT assay, fluorescence imaging, flow cytometry analysis, and in vivoantitumor efficacy were performed to evaluate the function of the Dox-DNA nanostructure complex.
In this study, a novel electrochemical sensing strategy was developed based on nontarget-induced bridge assembly and aptamer (Apt) extension reaction triggered by terminal deoxynucleotidyl transferase (TdT). Bisphenol A (BPA) was chosen as the target analyte to study the analytical performance of the designed aptasensor. This sensing system takes advantages of electrochemical sensing platforms and detection of an ultra-low level of BPA, due to the formation of bridge on the surface of electrode in the absence of BPA.
View Article and Find Full Text PDFAs one of the most toxic mycotoxins, aflatoxin B (AFB) is a major food pollutant which can pose a high risk to human health. In this work, an accurate fluorescent sensing method was proposed for AFB determination, based on hairpin structure of G-quadruplex oligonucleotide-Aptamer chimera, silica nanoparticles coated with streptavidin (SNPs-Streptavidin) and N-methyl mesoporphyrin IX (NMM). The hairpin structure of chimera and SNPs-Streptavidin allowed AFB detection with high sensitivity and specificity.
View Article and Find Full Text PDFKanamycin is an aminoglycoside antibiotic that can be useful against both gram negative and positive bacteria. However, if its serum levels are not controlled properly, it can cause serious side effects like ototoxicity and nephrotoxicity. The aim of this study was to design a simple and rapid fluorescent aptasensor for detection of kanamycin, based on Aptamer/Complementary strand (dsDNA)-capped mesoporous silica nanoparticles (MSNs) and Rhodamine B as a fluorescent probe.
View Article and Find Full Text PDFIn this study, a novel electrochemical aptasensor was developed for detection of AFM aflatoxin M (AFM) based on the hairpin-shaped structure of AFM aptamer (Apt), gold nanoparticles (AuNPs) and complementary strand of the aptamer (CS). The conformational change of hairpin structure of Apt in the presence and absence of AFM and also negatively charged AuNPs allowed detection of AFM with high sensitivity and selectivity. In the absence of the AFM, the hairpin structure of the Apt was intact.
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