Abstract: The present invention relates, in general terms, to nanoparticle solutions, kits, devices and methods of use thereof. The present invention is suitable for use in quantifying bacterial cells in a sample. The method of quantifying bacterial cells in a sample comprises passing the sample in a liquid form and an aqueous nanoparticle solution through a porous substrate such that the bacterial cells in the sample is trapped on the porous substrate and can be quantified by a colorimetric and/or fluorescence output emitted from the nanoparticle bound to the bacterial cells.

Abstract: The present invention relates to a nanosensor for detecting SARS-CoV-2 specific antibodies, wherein the nanosensor comprises a metal nanoparticle functionalised with one or more B-cell linear peptide epitopes derived from the spike (S) protein or nucleocapsid (N) protein of SARS-CoV-2. In some preferred embodiments, the metal nanoparticle comprises gold, silver, or a combination of gold and silver. The present invention also relates to various methods involving the use of the nanosensor.

Abstract: The disclosure concerns bacterial cell counting devices, systems and methods thereof. The bacterial cell counting device comprises at least one cartridge for containing reagents; an inlet for introducing a sample containing bacterial cells into the device; an optofluidic chip separately in fluid communication with the cartridge and the inlet; a filter strip passing through the optofluidic chip and in fluid communication with the cartridge and the inlet, the filter strip for trapping or retaining bacterial cells on its surface such that the bacterial cells can interact with the reagents as they flow through the filter strip; and a controller for controlling a sequential flow of reagents and sample to the filter strip via the optofluidic chip. The optofluidic chip is capable of detecting a colorimetric and/or fluorescence output emitted from the bacterial cells modified by the reagents in order for the bacterial cells to be quantified relative to a control.

Abstract: There is provided herein a paper-based sensor for simultaneously determining a plurality of biomarkers present in a biological sample comprising a plurality of detection zones in fluid communication with a sampling zone, wherein said plurality of detection zones comprises sensing material specific to each of said plurality of biomarkers. There is also provided herein a method of manufacturing the paper-based sensor, a use of a paper-based sensor for wound diagnosis, a kit comprising the paper-based sensor and a method of diagnosing wound health.

Abstract: The present invention relates, in general terms, to nanoparticle solutions, kits, devices and methods of use thereof. The present invention is suitable for use in quantifying bacterial cells in a sample. The method of quantifying bacterial cells in a sample comprises passing the sample in a liquid form and an aqueous nanoparticle solution through a porous substrate such that the bacterial cells in the sample is trapped on the porous substrate and can be quantified by a colorimetric and/or fluorescence output emitted from the nanoparticle bound to the bacterial cells.

Abstract: This disclosure relates to a sensor that detects bacteria cells comprising (a) a primary negatively charged, nanoparticulate sensing material; (b) a secondary positively charged, fluorescent sensing material; (c) a housing; and (d) at least one illuminator. This disclosure further relates to a method for detecting bacteria cells.

Abstract: This invention relates to a sensor that detects bacteria cells comprising (a) a primary negatively charged, nanoparticulate sensing material; (b) a secondary positively charged, fluorescent sensing material; (c) a housing; and (d) at least one illuminator; wherein said housing contains said primary negatively charged, nanoparticulate sensing material, said secondary positively charged fluorescent sensing material and a sample potentially comprising bacteria in aqueous medium, wherein said illuminator provides light of at least one pre-specified wavelength ?i to excite at least said secondary positively charged, fluorescent material, wherein said secondary positively charged, fluorescent material electrostatically attached to bacteria cells provides at least one fluorescent response at a second different wavelength ?n wherein both i and n are integers, wherein said negatively charged, nanoparticulate sensing material electrostatically attached to said fluorescent material suppresses fluorescing of said fluores

Abstract: The present invention provides a sensor for sensing nucleic acid-protein interactions, comprising a noble metal nanoparticle (NP), a double stranded nucleic acid molecule capable of binding with a protein in an aqueous solution and a fluorescent conjugated polymer (CP). The present invention also provides a method for sensing nucleic acid-protein interactions with the sensor as defined above.

Abstract: A system for measuring presence and/or amount of a target antibody in a sample comprising a nanoparticle adapted to quench fluorescence emission, an Fc binding protein immobilized or absorbed on the nanoparticle, and a fluorescing antibody adapted for binding to the Fc binding protein and having a lower binding affinity to the Fc binding protein than the target antibody. According to further embodiments of the present invention, methods of measuring presence and/or amount of a target antibody in a sample are also provided. The methods comprise mixing the sample with the components of the system and measuring the change in fluorescent intensity as compared to the total fluorescent intensity before the mixing.

Abstract: The present invention refers to a method of determining protein-nucleic acid interaction. The method comprises mixing a protein with a sample comprising a nucleic acid which is suspected to interact with the protein to form a first mixture. The first mixture can be incubated to allow interaction between the protein and nucleic acid. Metallic nanoparticles are added to the first mixture to obtain a second mixture. An electrolyte is added to the first or second mixture to determine the protein-nucleic acid interaction. The present invention also refers to a kit for determining protein-nucleic acid interaction. The kit comprises a protein capable of interacting with a nucleic acid or a nucleic acid capable of interacting with a protein, and at least one type of metallic nanoparticle.

Abstract: The present invention relates to a method of forming polymer substrate with variable refractive index sensitivity, the method comprising the steps of: (a) contacting a metal-coated patterned mold with a polymer substrate at a temperature sufficient to deform said polymer substrate to thereby deposit a patterned mask of a metal film on the polymer substrate; and (b) etching away portions of said polymer substrate not covered by said patterned mask under conditions to form a region of variable refractive index sensitivity on said polymer substrate.

Abstract: The present invention provides a sensor for sensing nucleic acid-protein interactions, comprising a noble metal nanoparticle (NP), a double stranded nucleic acid molecule capable of binding with a protein in an aqueous solution and a fluorescent conjugated polymer (CP). The present invention also provides a method for sensing nucleic acid-protein interactions with the sensor as defined above.

Abstract: The present invention provides a colorimetric method for detecting a polynucleotide strand binding molecule using one type of metal particles modified with a single type of interacting molecules. The interacting molecule is capable of specifically binding to nucleic and of protecting the metal particle from aggregation. Furthermore, the metal particles are capable of aggregation upon salt aggregation and/or cleavage of the interacting molecule, and colorimetric change changes upon aggregation.

Abstract: There is provided a method for detecting binding of a DNA-binding protein to a target recognition sequence. The method comprises mixing in a reaction buffer a first set of metal nanoparticles, a second set of metal nanoparticles and a DNA-binding protein to form a mixture, and detecting the aggregation state of the mixture of metal nanoparticles. Each set of metal nanoparticles has a conjugated double-stranded DNA molecule having a single-stranded overhang at one end. The single-stranded overhangs of each set of DNA-conjugated metal nanoparticles are complementary to each other such that annealing of the complementary overhangs results in formation of the target recognition sequence that specifically binds the DNA-binding protein. The reaction buffer comprises an ionic species in a concentration sufficient to result in aggregation of the metal nanoparticles upon annealing of the first and second single-stranded overhang.

Abstract: The present invention relates to a method of forming polymer substrate with variable refractive index sensitivity, the method comprising the steps of: (a) contacting a metal-coated patterned mold with a polymer substrate at a temperature sufficient to deform said polymer substrate to thereby deposit a patterned mask of a metal film on the polymer substrate; and (b) etching away portions of said polymer substrate not covered by said patterned mask under conditions to form a region of variable refractive index sensitivity on said polymer substrate.

Abstract: There is provided a method for detecting binding of a DNA-binding protein to a target recognition sequence. The method comprises mixing in a reaction buffer a first set of metal nanoparticles, a second set of metal nanoparticles and a DNA-binding protein to form a mixture, and detecting the aggregation state of the mixture of metal nanoparticles. Each set of metal nanoparticles has a conjugated double-stranded DNA molecule having a single-stranded overhang at one end. The single-stranded overhangs of each set of DNA-conjugated metal nanoparticles are complementary to each other such that annealing of the complementary overhangs results in formation of the target recognition sequence that specifically binds the DNA-binding protein. The reaction buffer comprises an ionic species in a concentration sufficient to result in aggregation of the metal nanoparticles upon annealing of the first and second single-stranded overhang.

Abstract: There is disclosed a method and system for detecting a surface plasmon resonance associated with a fluid sample. The method includes the step of providing a piezoelectric substrate having at least two electrodes thereon, wherein at least one of said electrodes is coupled to a fluid sample. A light beam is transmitted toward the fluid sample to induce a oscillation frequency in the piezoelectric substrate. The oscillation frequency from said electrodes is then measured during transmittance of the light to detect the surface plasmon resonance associated with the fluid sample.

Abstract: The present invention refers to a method of determining protein-nucleic acid interaction. The method comprises mixing a protein with a sample comprising a nucleic acid which is suspected to interact with the protein to form a first mixture. The first mixture can be incubated to allow interaction between the protein and nucleic acid. Metallic nanoparticles are added to the first mixture to obtain a second mixture. An electrolyte is added to the first or second mixture to determine the protein-nucleic acid interaction. The present invention also refers to a kit for determining protein-nucleic acid interaction. The kit comprises a protein capable of interacting with a nucleic acid or a nucleic acid capable of interacting with a protein, and at least one type of metallic nanoparticle.

Abstract: The present invention is directed to a method of detecting presence or absence of a target nucleic acid using negatively charged metallic nanoparticles dissolved in a solution. A nucleic acid probe with a substantially neutral net charge is used for detecting the target nucleic acid. The present invention is also directed to a kit including at least one nucleic acid probe with a substantially neutral net charge and at least one type of negatively charged metallic nanoparticles for carrying out the method.

Abstract: There is provided a resonator sensor useful for detecting polymorphisms and mutations in DNA. The resonator sensor has a capture molecule immobilised on its surface, the capture molecule being either a probe DNA containing a reference sequence, or a mismatch binding molecule, and being capable of forming a probe DNA/target DNA/mismatch binding molecule complex on the surface of the resonator. A method for detecting mutations in a target DNA, including single nucleotide polymorphisms, is also provided.