Disclosed herein is a biosensor for optical detection of Brownian relaxation dynamics of magnetic particles measured by light transmission. The magnetic particles can be functionalized with biological ligands for the detection of target analytes in a sample.

A digitally encoded microflake includes a polymer layer, which has a top surface and a bottom surface substantially parallel to the top surface. At least one of the top surface and the bottom surface is to be coupled to target-specific probes for bonding with a target analyte. The microflake is identified by a binary sequence of bits encoded by an edge outline on a plane substantially parallel to the top surface and the bottom surface. The bits in the binary sequence are encoded at respective predefined locations surrounding the edge outline.

The present invention generally relates to droplet libraries and to systems and methods for the formation of libraries of droplets. The present invention also relates to methods utilizing these droplet libraries in various biological, chemical, or diagnostic assays.

Some embodiments of the present disclosure are directed to systems and methods for separating, directing, and/or extracting a target molecule from a mix of molecules and may comprise a plurality of non-magnetic beads suspended in a ferro fluid, where the non-magnetic beads may be functionalized with at least one predetermined first molecule configured to bind with a target particle. A microfluidic device may be included which may comprise at least one microfluidic channel, the device configured to dynamically and/or statically receive an amount of the mix. Magnetic field means may be included and may be configured to apply a magnetic field to at least a portion of the at least one channel to exert an indirect force on the non-magnetic heads in the ferro fluid mix, and separate the non-magnetic beads from the ferrofluid. The beads may then be directed to at least one receptor region. At least one outlet may be provided which is arranged to be in communication with the at least one microfluidic channel, the at least one outlet may be configured to receive and extract the separated non-magnetic beads from the ferrofluid.

A bio-related substance assay tube 2 comprises a target substance capture bead 3 serving as a first microparticle, compensation bead 4 serving as a second microparticle on which a given amount of a bio-related substance has been immobilized, and a negative control bead 5 serving as a third microparticle for use as a negative control. A mount unit 12 comprises a nozzle communicating with a pump, and the bio-related substance assay tube 2 is mounted in the mount unit 12 to ensure communication with this nozzle. An analyte is introduced into the bio-related substance assay tube 2, followed by labeling the bio-related substance bound to each microparticle to cause light emission. Based on light emission from each microparticle, a calibration curve is prepared or the emission intensity of the first microparticle is compensated to quantify the bio-related substance.

The present invention relates to a process for detecting a virus that include the steps of: taking a biosample (e.g. saliva) suspected of containing a virus, mixing it with a solution comprising nanoparticles having easily detectable properties (e.g. a color) and also comprising contrasting microparticles (e.g. clear or white), each having attached chemical compounds (e.g. antibodies) that selectively bind to the virus to be detected (e.g. SARS-CoV-2). When suitably mixed together, virus present in the biosample may bind to the nanoparticles and to the microparticles, connecting the two. When the mixture is then passed through a microfluidic assembly with dimensions that trap the microparticles but pass unbound nanoparticles, the detection of the presence of nanoparticles bound to the microparticles at the microfluidic filter indicates the presence of the virus to be detected. The process may include a concentration step to accelerate binding the virus to the nano- and micro-particles.

Macroporous beads and a method of manufacturing and using such macroporous beads. wherein the beads are distinguishable for use in a multiplex assay. Preferably, the beads are distinguishable by two or more unique fluorochromes, and at least some of the beads are magnetically responsive. In a preferred form, some of the macroporous beads have interior pores with a different moiety from the exterior surface, allowing beads with different attached functional groups.

In various embodiments methods are provided for identifying and/or quantifying one or more antigens of interest (biomarkers) on the surface of cell- or tissue-specific exosomes. In an illustrative embodiments the methods comprise: i) incubating a population of exosomes with one or more tissue-specific antibodies that bind an antigen specific to a tissue or cell type of interest that produces exosomes, where the tissue specific antibodies are attached to acceptor bead or magnetic beads so the antibodies bind exosomes displaying the antigen; ii) obtaining a purified population of exosomes bound by the tissue specific antibodies with and/or without photocleavable linker based technology; iii) incubating a test subset of the isolated tissue-specific exosomes with acceptor beads attached to test antibodies that bind an antigen of interest thereby binding exosomes that display the antigen of interest and a control subset with negative control acceptor beads; v) incubating the test subset of isolated exosomes and the control subset of exosomes with a donor-bearing antibody that binds an exosome specific antigen; and vi) detecting a signal produced upon illumination of the control subset and/or the test; and vii) detecting the antigen(s) of interest.

Systems and methods are provided for detecting one or more particles such as individual unlabeled molecules or single nanoparticles. In examples described herein, optical energy is introduced into a microtoroid or other microcavity to generate an evanescent field. The microcavity has a functionalized outer surface that has been functionalized with a chemically or biologically active substance such as an antibody, antigen or protein. An indication of a particle bound to the functionalized outer surface of the microcavity is then detected based on a reactive interaction between the particle and the evanescent field while using frequency locking, balanced detection and various filtering techniques. The frequency locking, balanced detection and filtering techniques reduce the signal-to-noise ratio (SNR) of the detection system so that single nanoparticles (e.g. 2.5 nanometers (nm) in radius) and individual molecules (e.g. 15.5 kilo-Dalton (kDa) in size) can be detected in aqueous solution in some examples.

There are disclosed a method for determining binding constants between a substance or a substance mixture and a target, and a kit for carrying out the method according to the invention. The binding constants of the substance for the targets are determined by shifting the binding equilibrium. The concentrations of the immobilised and the dissolved target, are varied and the affinities with the targets are determined by shifting the binding equilibria in the individual batches.