Ultrasensitive point-of-care multiplex diagnosis for influenza virus based robust quantum dot microsphere-lateral flow immunoassay.

Influenza A virus (IAV) and influenza B virus (IBV) with similar symptoms of infection caused a serious disease burden and economic losses in annual epidemic season, so it is important to quickly and accurately detect and distinguish between IAV and IBV during influenza season. Herein, the quantum dot microspheres (QDMS) were synthesized and applied to lateral flow immunoassays (LFIA), and a point-of-care (POC) biosensor that can discriminately and simultaneously diagnose IAV and IBV within 10 min was established. A double-sandwich QDMS nanotags was synthesized by immobilizing hydrophobic quantum dots (QDs) with chemical bonding method on a silica sphere template with an outer silica shell protection showed excellent stability and high fluorescence.

Tailored different sizes of quantum dot nanobeads for sensitive and quantitative detection based on the competition fluorescence-linked immunosorbent assay platform.

Highly stable and multicolor photoluminescent (PL) quantum dots (QDs) have attracted widespread attention as ideal probe materials in the field of in vitro diagnostics (IVD), especially the fluorescence-linked immunosorbent assay (FLISA), due to their advantages of high-throughput, high stability, and high sensitivity. However, the size of QDs as fluorescent probes have significant effects on antigen-antibody performance. Therefore, it is critical to design suitable QDs for obtain excellent quantitative detection-based biosensors.

Highly Sensitive, Stable InP Quantum Dot Fluorescent Probes for Quantitative Immunoassay Through Nanostructure Tailoring and Biotin-Streptavidin Coupling.

Nontoxic, highly sensitive InP quantum dot (QD) fluorescent immunoassay probes are promising biomedical detection modalities due to their unique properties. However, InP-based QDs are prone to surface oxidation, and the stability of InP QD-based probes in biocompatible environments remains a crucial challenge. Although the thick shell can provide some protection during the phase transfer process of hydrophobic QDs, the photoluminescence quantum yield (PLQY) is generally decreased because of the contradiction between lattice stress relaxation and thick shell growth.

Development of a Dual Fluorescence Signal-Enhancement Immunosensor Based on Substrate Modification for Simultaneous Detection of Interleukin-6 and Procalcitonin.

High-sensitivity detection of biomarkers is of great significance to improve the accuracy of disease diagnosis and the rate of occult disease diagnosis. Using a substrate modification and two-color quantum dot (QD) nanobeads (QBs), we have developed a dual fluorescence signal-enhancement immunosensor for sensitive, simultaneous detection of interleukin 6 (IL-6) and procalcitonin (PCT) at low volumes (∼20 μL). First, the QBs compatible with QDs with different surface ligands were prepared by optimizing surfactants based on the microemulsion method.

Tailored three-color quantum dots nanobeads for multiplexed detection with tunable detection range and multilevel sensitivity of signal-amplified immunosensor.

The excellent optical properties of quantum dots (QDs) make them as an ideal fluorescent probe for multiplexed detection, however, the interference between different emission spectra, the dependence of excitation wavelengths, and the sharp decrease of quantum yield (QY) during surface modification are issues that cannot be ignored. Herein, a dual protection scheme of polymer and silica was proposed to prepare high-quality three-color QDs nanobeads using QDs with different ligands. In comparison with single-core QDs, the fluorescence signal of the prepared QD nanobeads (QBs) is increased by more than 1,000 times and has better stability.

Aminophosphate precursors for the synthesis of near-unity emitting InP quantum dots and their application in liver cancer diagnosis.

InP quantum dots (QDs) are a promising and environment-friendly alternative to Cd-based QDs for in vitro diagnostics and bioimaging applications. However, their poor fluorescence and stability severely limit their biological applications. Herein, we synthesize bright (∼100%) and stable InP-based core/shell QDs by using cost-effective and low-toxic phosphorus source, and then aqueous InP QDs are prepared with quantum yield over 80% by shell engineering.

Recent advances in quantum dot-based fluorescence-linked immunosorbent assays.

Fluorescence immunoassays have been given considerable attention among the quantitative detection methods in the clinical medicine and food safety testing fields. In particular, semiconductor quantum dots (QDs) have become ideal fluorescent probes for highly sensitive and multiplexed detection due to their unique photophysical properties, and the QD fluorescence-linked immunosorbent assay (FLISA) with high sensitivity, high accuracy, and high throughput has been greatly developed recently. In this manuscript, the advantages of applying QDs to FLISA platforms and some strategies for their application to diagnostics and food safety are discussed.

Fabrication of CuInZnS/ZnS Quantum Dot Microbeads by a Two-Step Approach of Emulsification-Solvent Evaporation and Surfactant Substitution and Its Application for Quantitative Detection.

CuInS quantum dots (CIS QDs) are considered to be promising alternatives for Cd-based QDs in the fields of biology and medicine. However, high-quality hydrophobic CIS QDs are difficult to be transferred to water due to their 1-dodecylmercaptan (DDT) ligands. Therefore, the fluorescence and stability of the prepared aqueous CIS QDs is not enough to meet the requirement for sensitive detection.

Establishment of a Ca(II) ion-quantum dots fluorescence signal amplification sensor for high-sensitivity biomarker detection.

Quantum dots (QDs) have been considered as the promising fluorescent labeling material, which is expected to meet the requirement of high-sensitivity detection in clinical diagnostics. Some common metal ions are known to affect the stability and fluorescence properties of QDs, but scarcely any systematic research has been done about their impacts on QD-based bio-detection. By evaluating the effect of Ca metal ions on the properties of aqueous QDs, a new metal ion-QD fluorescence signal amplification sensor (i.

Self-assembly strategy to reduce non-specific adsorption for the development of high sensitivity quantitative immunoassay.

The development of functionalized surfaces with low non-specific adsorption is important for their biomedical applications. To inhibit non-specific adsorption on glass substrate, we designed a novel optical biochip by modifying a layer of dense negatively charged film (SO) on its substrate surface via self-assembly. Compared with the untreated glass substrate, it reduced the adsorption by about 300-fold or 400-fold by poly (styrene sulfonic acid) sodium salt (PSS), or meso-tetra (4-sulfonatophenyl) porphine dihydrochloride (TSPP) on individually the modified glass substrate.

Biomolecular Surface Functionalization and Stabilization Method to Fabricate Quantum Dots Nanobeads for Accurate Biosensing Detection.

The surface functionalization of quantum dots (QDs) is essential for their application as a label material in a biological field. Here, a protein surface functionalization approach was introduced to combine with silica encapsulation for the sustainable and stable synthesis of QDs nanobeads for biomarker detection. The formation of QDs nanobeads was achieved by multiple mercapto groups in bovine serum albumin (BSA) macromolecules as multidentate ligands to replace hydrophobic ligands on the surface of QDs and decompression.

A quantum dot microspheres-based highly specific and sensitive three-dimensional microarray for multiplexed detection of inflammatory factors.

The development trend ofdiagnostics is to obtain various biological information from a sample at extremely low concentration and volume, which has promoted its progress in accurate and sensitive multiplexed detection. Here, we developed a single color quantum dot (QD) based three-dimensional (3D) structure matrix microarray and conducted the detection of two inflammatory factors (C-reactive protein (CRP) and serum amyloid A (SAA)) by a self-built fluorescence detection system. This strategy increased detection sensitivity by immobilizing the antibody specifically on the 3D substrate because it captured more than about 7 times of 'effective' antibodies compared to the two-dimensional (2D) plane.

Sensitive Immunoassay Based on Biocompatible and Robust Silica-Coated Cd-Free InP-Based Quantum Dots.

Low-toxic InP quantum dots (QDs) as an ideal candidate for Cd-based QDs have tremendous potential for next-generation commercial display and biological detection applications. However, the progress in biological detection is still far behind that of the Cd-based QDs. This is mainly because the InP-based QDs are of inferior stability and photoluminescence quantum yield (PL QY) in aqueous solution.

Functional Connectivity Differences in the Insular Sub-regions in Migraine without Aura: A Resting-State Functional Magnetic Resonance Imaging Study.

The objective of this study was to investigate resting-state functional connectivity (FC) differences in insular sub-regions during the interictal phase in patients with migraine without aura (MWoA). Forty-nine MWoA patients (MWoA group) and 48 healthy individuals (healthy control group) were recruited for this study. All of the subjects underwent neurological examination and magnetic resonance imaging (MRI).

Synthesis of Reabsorption-Suppressed Type-II/Type-I ZnSe/CdS/ZnS Core/Shell Quantum Dots and Their Application for Immunosorbent Assay.

We report a phosphine-free one-pot method to synthesize ZnSe/CdS/ZnS core-shell quantum dots (QDs) with composite type-II/type-I structures and consequent reabsorption suppression properties. The as-synthesized QDs possess high efficient red emission (with quantum yield of 82%) and high optical stability. Compared to type-I QDs, the ZnSe/CdS/ZnS QDs show larger Stokes shift and lower reabsorption which can reduce the emission loss and improve the level of fluorescence output.

Highly sensitive and accurate detection of C-reactive protein by CdSe/ZnS quantum dot-based fluorescence-linked immunosorbent assay.

Background: The conventional and widely used enzyme-linked immunosorbent assays (ELISA), due to specificity and high-sensitivity, were suitable in vitro diagnosis. But enzymes are vulnerable to the external conditions, and the complex operation steps limit its application. Semiconductor quantum dots have been successfully used in biological and medical research due to the high photoluminescence and high resistance to photobleaching.

Different mean thickness implicates involvement of the cortex in migraine.

The results of neuroimaging studies on migraines have shown that the functions and functional connectivity networks of some brain regions are altered in migraine patients, and different brain structure volumes have also been observed in recent years. However, it is still not known whether the mean thickness of the cortex is different in migraine patients.A total of 48 migraine without aura (MWoA) patients in interictal phase and 48 healthy controls were enrolled in this study.