A fluorescence and colorimetric dual-mode aptasensor for kanamycin detection.

This study presents the development of a dual-mode aptasensor for the sensitive detection of kanamycin (KAN), utilizing both fluorescence and colorimetric signals. The aptasensor was constructed using amino-functionalized silica nanoparticles (SiO) combined with copper nanoclusters (CuNCs) and DNA-templated silver nanoclusters (DNA-AgNCs). Encapsulating CuNCs within SiO (CuNCs@SiO) enhanced their stability by shielding them from environmental interference, while maintaining their bright blue fluorescence as a reference signal.

Strap-on Buoyant Device to Enhance Gastrointestinal Tract Retention of Felodipine Osmotic Pump Tablets.

Osmotic pump systems require prolonged retention time in the stomach to provide enhanced bioavailability and regulated release, which is quite challenging. This study used a three-dimensional printing (3DP) technique combined with a gastro-retentive floating device (GRFD) to extend the retention of the osmotic pump in the stomach and enhance its bioavailability. The strap-on buoyant device was fabricated by stereolithography 3DP and incorporated a felodipine osmotic pump tablet used in clinical practice, which enabled it to float in the stomach or dissolution media without any floating lag time.

Polystyrene Sulfonate Resin as an Ophthalmic Carrier for Enhanced Bioavailability of Ligustrazine Phosphate Controlled Release System.

Topical ocular sustained-release drug delivery systems represent an effective strategy for the treatment of ocular diseases, for which a suitable carrier has yet to be sufficiently developed. Herein, an eye-compatible sodium polystyrene sulfonate resin (SPSR) was synthesized with a uniform particle size of about 3 μm. Ligustrazine phosphate (LP) was adsorbed to SPSR by cation exchange to form LP@SPSR.

Controlled release of vitamin A palmitate from crosslinked cyclodextrin organic framework for dry eye disease therapy.

Controlled release drug delivery systems of eye drops are a promising ophthalmic therapy with advantages of good patient compliance and low irritation. However, the lack of a suitable drug carrier for ophthalmic use limits the development of the aforementioned system. Herein, the crosslinked cyclodextrin organic framework (COF) with a cubic porous structure and a uniform particle size was synthesized and applied to solidify vitamin A palmitate (VAP) by using the solvent-free method.

Reverse design of haptens based on antigen spatial conformation to prepare anti-capsaicinoids&gingerols antibodies for monitoring of gutter cooking oil.

Rapid simultaneous detection of multi-component adulteration markers can improve the accuracy of identification of gutter cooking oil in edible oil, which is made possible by broad-spectrum antibody (bs-mAb). This study used capsaicinoids (CPCs) and gingerol derivatives (GDs) as adulteration markers, and two broad-spectrum haptens (bs-haptens) were designed and synthesized based on a reverse design strategy of molecular docking. Electrostatic potential (ESP) and monoclonal antibodies (mAbs) preparation verified the strategy's feasibility.

Silver/copper bimetallic nanoclusters integrating with cryonase-assisted target recycling amplification detection of Salmonella typhimurium.

An unsophisticated fluorescence-enabled strategy is brought forward to process the highly sensitive fluorescence detection of Salmonella typhimurium (S. typhimurium) which based on polyethyleneimine (PEI)-templated silver/copper nanoclusters (Ag/CuNCs) (λ excitation = 334 nm and λ emission = 466 nm) with cryonase-assisted target recycling amplification. The Ag/CuNCs nanoclusters are synthesized as fluorescent materials due to their strong and stable fluorescence characteristics and are modified with S.

Development of a fluorescent sensor based on TPE-Fc and GSH-AuNCs for the detection of organophosphorus pesticide residues in vegetables.

A novel dual-signal fluorescent sensor was developed for detecting organophosphorus pesticides (OPs). It relies on the catalytic activities of acetylcholinesterase (AChE) and choline oxidase (ChOx) to generate hydrogen peroxide (HO) through the conversion of acetylcholine (ACh) to choline·HO then oxidizes ferrocene-modified tetraphenylethylene (TPE-Fc) to its oxidized state (TPE-Fc), resulting in enhanced cyan fluorescence due to aggregation. Simultaneously, ferrocene oxidation generates hydroxyl radicals (•OH), causing a decrease in orange fluorescence of glutathione-synthesized gold nanoclusters (GSH-AuNCs).

Paper-based biosensors relying on core biological immune scaffolds for the detection of procymidone in vegetables.

In order to achieve a highly sensitive detection of procymidone in vegetables, three paper-based biosensors based on a core biological immune scaffold (CBIS) were developed, which were time-resolved fluorescence immunochromatography strips with Europium (III) oxide (Eu-TRFICS). Goat anti-mouse IgG and europium oxide time-resolved fluorescent microspheres formed secondary fluorescent probes. CBIS was formed by secondary fluorescent probes and procymidone monoclonal antibody (PCM-Ab).

Label-free colorimetric apta-assay for detection of based on gold nanoparticles with peroxidase-like amplification.

In this work, aptamers against with better performance were obtained cell systematic evolution of ligands by exponential enrichment (cell-SELEX) and dissociation constants (Kd) of aptamers were estimated to range from 133.87 to 199.44 nM.

Novel Dual-Signal SiO-COOH@MIPs Electrochemical Sensor for Highly Sensitive Detection of Chloramphenicol in Milk.

In view of the great threat of chloramphenicol (CAP) to human health and the fact that a few producers have illegally used CAP in the food production process to seek economic benefits in disregard of laws and regulations and consumer health, we urgently need a detection method with convenient operation, rapid response, and high sensitivity capabilities to detect CAP in food to ensure people's health. Herein, a molecularly imprinted polymer (MIP) electrochemical sensor based on a dual-signal strategy was designed for the highly sensitive analysis of CAP in milk. The NiFe Prussian blue analog (NiFe-PBA) and SnS nanoflowers were modified successively on the electrode surface to obtain dual signals from [Fe(CN)] at 0.

Isolation of Bacteria Aptamers with Non-SELEX for the Development of a Highly Sensitive Colorimetric Assay Based on Dual Signal Amplification.

In this work, an aptamer against is isolated via non-SELEX, which executes efficient selection by employing repetitive cycles of centrifugation-based partitioning, and the binding site of the aptamer on cell surfaces is inferred to be a membrane protein. Moreover, truncated sequence 2-17-2 with a higher affinity ( = 101.76 nM) is employed for highly sensitive colorimetric detection of bacteria based on the dual signal amplification strategy.

Dual-target electrochemical DNA sensor for detection of Pb and Hg simultaneously by exonuclease I-assisted recycling signal amplification.

With the development of exonuclease, the exonuclease has been used to construct a variety of aptasensor and to realize the signal amplification. Among them, based on silver nanoparticles (Ag NPs) and exonuclease I (Exo I)-assisted cycle signal amplification strategy, we designed a novel high-sensitivity dual-target electrochemical biosensor to detect Pb or Hg in water. In the presence of Hg, the Hgwas fixed to the aptamer chain by thymine-Hg-thymine (T-Hg-T), resulting in the decrease of signal.

The Effects of Different Antigen-Antibody Pairs on the Results of 20 Min ELISA and 8 Min Chromatographic Paper Test for Quantitative Detection of Acetamiprid in Vegetables.

To establish rapid, high-sensitive, quantitative detection of ACP residues in vegetables. A 1G2 cell clone was selected as the most sensitive for anti-ACP antibody production following secondary immunization, cell fusion, and screening. The affinity of the 1G2 antibody to each of the four coating agents (imidacloprid−bovine serum albumin [BSA], thiacloprid−BSA, imidaclothiz−BSA, and ACP-BSA) was determined using a 20 min enzyme-linked immunosorbent assay (ELISA).

Novel Electrochemical Aptasensor Based on Ordered Mesoporous Carbon/2D TiC MXene as Nanocarrier for Simultaneous Detection of Aminoglycoside Antibiotics in Milk.

Herein, a novel electrochemical aptasensor using a broad-spectrum aptamer as a biorecognition element was constructed based on a screen-printed carbon electrode (SPCE) for simultaneous detection of aminoglycoside antibiotics (AAs). The ordered mesoporous carbon (OMC) was firstly modified on 2D TiC MXene. The addition of OMC not only effectively improved the stability of the aptasensor, but also prevented the stacking of TiC sheets, which formed a good current passage for signal amplification.

Electrochemiluminescence biosensor for determination of lead(II) ions using signal amplification by Au@SiO and tripropylamine-endonuclease assisted cycling process.

MXene@Au as the base and Au@SiO as signal amplification factor were used for constructing an ultrasensitive "on-off" electrochemiluminescence (ECL) biosensor for the detection of Pb in water. The use of MXene@Au composite provided a good interface environment for the loading of tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)) on the electrode. Based on resonance energy transfer, the Au (core) SiO (shell) (Au@SiO) nanoparticles stimulate electron transport and promote tripropylamine (TPrA) oxidation.

Ultrasensitive electrochemiluminescence aptasensor based on ABEI reduced silver nanoparticles for the detection of profenofos.

An ultrasensitive electrochemiluminescence (ECL) aptasensor for detection of profenofos was constructed by the reducibility and chemiluminescence property of N-(aminobutyl)-N-(ethylisoluminol) (ABEI). ABEI was used to reduce silver nitrate (AgNO) to silver nanoparticles (AgNPs), which could be adsorbed on the lattice of graphene oxide (GO) to form ABEI-AgNPs-GO complex. This compound could achieve excellent luminescence.

Novel sandwich-type electrochemiluminescence aptasensor based on luminol functionalized aptamer as signal probe for kanamycin detection.

A novel sandwich electrochemiluminescence (ECL) aptasensor was developed for highly sensitive detection of kanamycin using luminol-functionalized aptamer as a signal probe. The aptasensor used polyethyleneimine (PAMAM), molybdenum disulfide, and multi-walled carbon nanotubes as the substrate, which provided enough binding sites for aptamer1 (the aptamer which modified NH) coupling. We found that kanamycin could be detected using the aptamer1 containing the same base sequence as aptamer2 (the aptamer which modified SH) on the electrode self-assembly.

Construction of a dual-model aptasensor based on G-quadruplexes generated via rolling circle amplification for visual/sensitive detection of kanamycin.

A dual-model colorimetric and electrochemical aptasensor was designed using a large number of G-quadruplexes generated by rolling circle amplification (RCA). Specific binding between target and aptamer during RCA yielded large numbers of G-quadruplexes. A colorimetric sensor was fabricated based on the interaction between the G-quadruplex and hemin, which altered the 3,3',5,5'-Tetramethylbenzidine (TMB)-catalyzed color reaction and facilitated the visual and semi-quantitative detection of kanamycin.

Non-immobilized GO-SELEX of aptamers for label-free detection of thiamethoxam in vegetables.

Due to the massive use of thiamethoxam (TMX) pesticide and the accumulated potential hazards exposure, the detection of TMX is of great significance to food and ecological safety. In this study, aptamers with affinity for TMX were obtained through graphene oxide assisted systematic evolution of ligands by exponential enrichment (GO-SELEX). After 9 rounds of positive and counter selection, 5 candidate sequences were obtained, among which seq.

Indirect signal amplification strategy with a universal probe-based lateral flow immunoassay for the rapid quantitative detection of fumonisin B1.

Fumonisin B1 (FB1) is a serious threat to the health of humans and animals. Herein, a lateral flow immunoassay based on universal detection probes (goat anti-mouse IgG@Eu) that could combine with any mouse monoclonal antibody was applied to detect FB1 in corn and feed. Compared with that based on direct monoclonal antibody labeling, this assay maintained bioactivity and saved consumption of monoclonal antibodies with the indirect signal amplification effect.

Recent advances in aptamer-based sensors for aminoglycoside antibiotics detection and their applications.

Aminoglycoside antibiotics (AAs) have been extensively applied in medical field and animal husbandry owing to desirable broad-spectrum antibacterial activity. Excessive AAs residues in the environment can be accumulated in human body through food chain and cause detrimental effect on human health. The establishment of highly specific, simple and sensitive detection methods for monitoring AAs residues is highly in demand.

Improving lipid productivity by engineering a control-knob gene in the oleaginous microalga .

spp. are promising industrial microalgae for scalable oil production and the lipid production can be boosted by nutrient starvation and high irradiance. However, these stimuli halt growth, thereby decreasing overall productivity.

Voltammetric determination of organophosphorus pesticides using a hairpin aptamer immobilized in a graphene oxide-chitosan composite.

An aptasensor is described for electrochemical determination of organophosphorus pesticides (OPPs), specifically of profenofos, phorate, isocarbophos, and omethoate. The method uses a hairpin aptamer as signalling donor. Its 5' and 3' ends were modified with amino groups and the redox probe ferrocene (Fc), respectively.

A dual-signal amplification strategy for kanamycin based on ordered mesoporous carbon-chitosan/gold nanoparticles-streptavidin and ferrocene labelled DNA.

An ultrasensitive electrochemical aptasensor for kanamycin (KAN) detection was constructed with a dual-signal amplification strategy. The aptasensor achieved greatly amplified sensitivity due to the excellent electrical conductivity of the ordered mesoporous carbon-chitosan (OMC-CS)/gold nanoparticles-streptavidin (AuNPs-SA) and DNA2 labelled with ferrocene (Fc-DNA2). The AuNPs-SA was used to immobilize the DNA strand (biotin labelled) with the biotin-streptavidin system.