Ultrasensitive Ochratoxin A Detection in Cereal Products Using a Fluorescent Aptasensor Based on RecJ Exonuclease-Assisted Target Recycling.

Ochratoxin A (OTA) is a mycotoxin widely found in foodstuffs such as cereal grains. It greatly threatens human health owing to its strong toxicity and high stability. Aptasensors have emerged as promising tools for the analysis of small molecule contaminants.

Ultrasensitive Detection Strategy of Norovirus Based on a Dual Enhancement Strategy: CRISPR-Responsive Self-Assembled SNA and Isothermal Amplification.

Spherical nucleic acids (SNAs) have been used to construct various nanobiosensors with gold nanoparticles (AuNPs) as nuclei. The SNAs play a critical role in biosensing due to their various physical and chemical properties, programmability, and specificity recognition ability. In this study, CRISPR-responsive self-assembled spherical nucleic acid (CRISPR-rsSNA) detection probes were constructed by conjugating fluorescein-labeled probes to the surface of AuNPs to improve the sensing performance.

A novel universal small-molecule detection platform based on antibody-controlled Cas12a switching.

Molecular diagnostics play an important role in illness detection, prevention, and treatment, and are vital in point-of-care test. In this investigation, a novel CRISPR/Cas12a based small-molecule detection platform was developed using Antibody-Controlled Cas12a Biosensor (ACCBOR), in which antibody would control the trans-cleavage activity of CRISPR/Cas12a. In this system, small-molecule was labeled around the PAM sites of no target sequence(NTS), and antibody would bind on the labeled molecule to prevent the combination of CRISPR/Cas12a, resulting the decrease of trans-cleavage activity.

N-doped molybdenum oxide quantum dots as fluorescent probes for the quantitative detection of copper ions in environmental samples.

A novel, sensitive, and selective fluorescence sensor based on N-doped Mo oxide quantum dots (N-MoOx QDs) was fabricated for the detection of Cu ions in water. The presence of Cu induced dynamic fluorescence quenching of the N-MoOx QDs. The sensing conditions were optimized to enhance selectivity and sensitivity.

Determination of Lincomycin in Milk Using Cu-Based Metal-Organic Framework Adsorbent and Liquid Chromatography-Tandem Mass Spectrometry.

Antibiotic drug residues can adversely affect the human body. Lincomycin is a common veterinary drug that can form residues in foods of animal origin. However, the detection of trace residue levels of lincomycin residues in real samples is challenging.

Ultrasensitive Automatic Detection of Small Molecules by Membrane Imaging of Single Molecule Assays.

Determination of trace amounts of targets or even a single molecule target has always been a challenge in the detection field. Digital measurement methods established for single molecule counting of proteins, such as single molecule arrays (Simoa) or dropcast single molecule assays (dSimoa), are not suitable for detecting small molecule, because of the limited category of small molecule antibodies and the weak signal that can be captured. To address this issue, we have developed a strategy for single molecule detection of small molecules, called small molecule detection with single molecule assays (smSimoa).

Design and synthesis of DNA hydrogel based on EXPAR and CRISPR/Cas14a for ultrasensitive detection of creatine kinase MB.

Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas systems exhibit significant potential in developing biosensing technology due to their collateral cleavage capabilities. Herein, we introduced the collateral cleavage activity of CRISPR/Cas14a to activate DNA hydrogel for ultrasensitive detection of the myocardial infarction biomarker creatine kinase MB (CK-MB). In this strategy, the designed CRISPR/Cas14a system can be activated by introducing complementary DNA (cDNA) derived from competitive dissociation and exponential amplification (EXPAR), which is positively correlated with creatine kinase isoenzyme (CK-MB) concentration.

Detection of ochratoxin A by fluorescence sensing based on mesoporous materials.

We developed a new ochratoxin A (OTA) aptamer biosensor to promptly detect OTA in food. Mesoporous silica nanoparticles were used as carriers, and aptamers were used as recognition probes and gating molecules. The fluorescent dye rhodamine 6G was loaded into mesoporous silica, and through electrostatic contact, the OTA aptamer was adsorbed on amino-modified mesoporous silica.

Aptamer-based photonic crystals enable ultra-trace detection of staphylococcal enterotoxin B without labels.

Staphylococcal enterotoxin B (SEB) is one of the most common serotypes in staphylococcal food-poisoning cases. A rapid, sensitive, and simple method for SEB detection is crucial for public health. A photonic crystal (PC) sensing material for label-free detection of ultra-trace SEB was proposed in this study.

A highly sensitive fluorometric biosensor for Fumonisin B1 detection based on upconversion nanoparticles-graphene oxide and catalytic hairpin assembly.

Fumonisin (FB) is a common mycotoxin in corn, wheat, oats, and their related products. FB1 is the most predominant among fumonisins and is responsible for severe food contamination that may have deleterious effects on public health. Therefore, the demand for achieving sensitive detection of FB1 is becoming more and more pressing.

A novel biosensor based on antibody controlled isothermal strand displacement amplification (ACISDA) system.

The overuse of antibiotics has aroused widespread concern in recent decades. Their residues in food and environment may pose potential risks to human health. Therefore, highly sensitive and rapid detection methods of antibiotics are urgently needed.

Bifunctional ligand-mediated amplification of polydiacetylene response to biorecognition of diethylstilbestrol for on-site smartphone detection.

Polydiacetylene (PDA) is very suited for sensitively detecting large biomolecules, and its unique chromatic properties enable visual read-out. However, application to the selective detection of small molecules remains challenging. Here, bifunctional ligands are studied to amplify the color change of PDA for biorecognition of small molecules for the smartphone-based detection of diethylstilbestrol (DES).

Target-responsive DNA hydrogel with microfluidic chip smart readout for quantitative point-of-care testing of creatine kinase MB.

Swift and effective diagnosis of acute myocardial infarction (AMI) is critical to patient survival due to its serious life-threatening effects and increasing incidence. Creatine kinase MB (CK-MB) is one of the markers of AMI. In this work, we enabled a portable visual quantitative assay of CK-MB by incorporating target-responsive DNA hydrogel with a microfluidic chip.

Highly Ordered, Plasmonic Enhanced Inverse Opal Photonic Crystal for Ultrasensitive Detection of Staphylococcal Enterotoxin B.

Although there is considerable interest in self-assembly of ordered, porous "inverse opal" structures for optical, electronic, and chemical applications, uncontrolled defect formation limits the usefulness of such materials. Herein, we develop a highly ordered and plasmonic enhanced sensing inverse opal photonic crystal (IOPC) material. The co-assembly of the colloidal template with the matrix material avoids the need for liquid penetration into the preassembled colloidal crystals and minimizes the associated rupture and inhomogeneity of the resulting IOPC.

Dual Sensitization Smartphone Colorimetric Strategy Based on RCA Coils Gathering Au Tetrahedra and Its Application in the Detection of CK-MB.

In recent years, the combination of DNA nanotechnology and biosensing has been extensively reported. Herein, we attempted to develop a dual sensitization smartphone colorimetric strategy based on rolling circle amplification (RCA) coils gathering Au tetrahedra and explore its application. The dual sensitization effect of this strategy was achieved by rolling circle amplification (RCA) and Au tetrahedra.

A highly sensitive method for simultaneous detection of hAAG and UDG activity based on multifunctional dsDNA probes mediated exponential rolling circle amplification.

DNA glycosylase is an indispensable DNA damage repair enzyme which can recognize and excise the damaged bases in the DNA base excision-repair pathway. The dysregulation of DNA glycosylase activity will give rise to the dysfunction of base excision-repair and lead to abnormalities and diseases. The simultaneous detection of multiple DNA glycosylases can help to fully understand the normal physiological functions of cells, and determine whether the cells are abnormal in pre-disease.

A fluorescence aptasensor based on controlled zirconium-based MOFs for the highly sensitive detection of T-2 toxin.

T-2 toxin is one of class A trichothecene mycotoxins produced by Fusarium, presenting genotoxic, cytotoxicity, and immunotoxicity for animals and humans. Therefore, It is urgent to establish a rapid test method with high sensitivity, good selectivity and reliability. In this research, by adjusting the synthesis conditions, a kind of NH-UiO-66 with high quenching efficiency was screened out.

A fluorescence aptasensor for the sensitive detection of T-2 toxin based on FRET by adjusting the surface electric potentials of UCNPs and MIL-101.

T-2 toxin is a class A trichothecene mycotoxin produced by Fusarium, which exhibits genotoxic, cytotoxic, and immunotoxic effects in animals and humans. In this study, we developed an aptasensor for the sensitive detection of T-2 toxin, which was based on fluorescence resonance energy transfer (FRET), and acted by adjusting the electric potential on the surface of upconversion nanoparticles (UCNPs) and MIL-101(Cr). In addition, it combined the excellent spectral properties of UCNPs with the good adsorption quenching abilities of metal organic frameworks (MOFs).

Ultrasensitive Detection of 17β-Estradiol (E2) Based on Multistep Isothermal Amplification.

17β-Estradiol (E2) can cause an adverse effect on the human endocrine system even at the nanomolar level. Measurements of very low levels of E2 remain a critical challenge due to insufficient sensitivity. In this study, a multistep isothermal amplification fluorescence strategy was constructed, which could realize the exponential amplification of target E2.

The orphan nuclear receptor Nur77 plays a vital role in BPA-induced PC12 cell apoptosis.

Bisphenol A (BPA) is a typical environmental endocrine disruptor that can migrate into organisms through skin contact, breathing, diet and various other approaches. The reproductive toxicity and neurotoxicity of BPA has been confirmed by several toxicological studies. However, the neurotoxicity of BPA is still controversial.

Immunosorbent assay based on upconversion nanoparticles controllable assembly for simultaneous detection of three antibiotics.

The abuse of antibiotics leads to an increase in resistant strains, which in turn leads to the development of superbugs that pose great difficulties for the treatment of human diseases. A high-throughput and highly sensitive avidin biotin complex immunosorbent assay based on upconversion nanoparticles controllable assembly (ABC-ULISA) for the detection of antibiotics was developed, which enabled accurate quantitative detection in a shorter period of time. Streptavidin and biotin-labeled upconversion nanoparticles form avidin-biotin-upconversion complex, which was then combined with biotinylated antibody to achieve double amplification of the signal, further improving detection sensitivity.

Development of a fast and ultrasensitive black phosphorus-based colorimetric/photothermal dual-readout immunochromatography for determination of norfloxacin in tap water and river water.

A rapid and ultrasensitive method for colourimetric/photothermal dual-readout detection was developed using an 808 nm NIR laser and a thermal imaging app on mobile phone. Norfloxacin was used as a model contaminant to demonstrate this universal rapid detection method. It is innovatively, to use the advanced two-dimensional material black phosphorus as a colourimetric/photothermal reagent for the first time.

Dual-emission ratio fluorescent probes based on carbon dots and gold nanoclusters for visual and fluorescent detection of copper ions.

Blue carbon dots (BCDs) and red gold nanoclusters modified by bovine serum albumin (BSA-Au NCs) were selected as luminescent nanomaterials, and the nanohybrid materials were successfully prepared and applied to the fluorescent measurement of copper ions. The prepared ratio fluorescent probe has two emission peaks near 452 and 654 nm under an excitation of 330 nm. The fluorescence intensity was gradually quenched because Au NCs was aggregated in the presence of Cu, resulting in a gradation of the fluorescent color from red to pink to purple to blue for visual detection.

A copper monosulfide-nanoparticle-based fluorescent probe for the sensitive and specific detection of ochratoxin A.

The mycotoxin ochratoxin A (OTA) is a secondary metabolite derived from multiple Aspergillus and Penicillium strains. The development of a rapid, sensitive, and simple method for OTA detection is important to ensure food biosafety and safeguard public health. In this study, we designed a highly specific and sensitive assay for the detection of OTA using copper monosulfide (CuS) nanoparticles conjugated to an anti-OTA antibody (CuS-Ab NPs) and a fluorescent probe for Cu.