Abstract: The present disclosure provides a graphene sensor and a preparation method and use thereof, and relates to the technical field of sensors. The graphene sensor according to the present disclosure includes a substrate, and an electrode layer and a functionalized graphene film that are laminated on a single side of the substrate, where the functionalized graphene film is obtained by modifying a graphene film with triethylamine. According to the present disclosure, the triethylamine is used as a probe to modify the graphene film, so that nitrate nitrogen can be sensitively and accurately measured. The graphene sensor according to the present disclosure identifies an object to be measured based on chemical functional groups instead of a biological method, and has low costs and high chemical stability.

Abstract: Provided herein are compositions and methods for analyzing neutralizing antibodies to SARS-CoV-2, for example, in a sample from a subject suspected of having, having, or having had (e.g., having recovered from) a SARS-CoV-2 infection, or a subject having received a prophylactic and/or therapeutic intervention for a coronavirus infection.

Abstract: An apparatus includes an interface to memory, and a processor to execute one or more instructions. The instructions cause the processor to receive, via an application programming interface (API), a plurality of packets, respective packets of the plurality of packets comprising a respective header and a respective payload. Further, the instructions cause the processor to determine, by a QUIC protocol stack, to encrypt the plurality of packets in parallel. Further, the instructions cause the processor to encrypt the payloads of the plurality of packets in parallel. Further, the instructions cause the processor to encrypt the headers of the plurality of packets in parallel.

Abstract: The present disclosure provides a graphene sensor and a preparation method and use thereof, and relates to the technical field of sensors. The graphene sensor according to the present disclosure includes a substrate, and an electrode layer and a functionalized graphene film that are laminated on a single side of the substrate, where the functionalized graphene film is obtained by modifying a graphene film with triethylamine. According to the present disclosure, the triethylamine is used as a probe to modify the graphene film, so that nitrate nitrogen can be sensitively and accurately measured. The graphene sensor according to the present disclosure identifies an object to be measured based on chemical functional groups instead of a biological method, and has low costs and high chemical stability.

Abstract: Provided herein are compositions and methods for analyzing neutralizing antibodies to SARS-CoV-2, for example, in a sample from a subject suspected of having, having, or having had (e.g., having recovered from) a SARS-CoV-2 infection, or a subject having received a prophylactic and/or therapeutic intervention for a coronavirus infection.

Abstract: This invention generally relates to the field of vitamin D detection. In particular, the invention provides novel methods and kits for assaying a vitamin D moiety in a sample such as a biological fluid.

Abstract: This invention relates generally to the field of homocysteine detection. In particular, the invention provides a method for determining homocysteine presence or concentration in samples, which method comprises: contacting a sample containing or suspected of containing Hcy with a Hcy co-substrate and a Hcy converting enzyme in a Hcy conversion reaction to form a Hcy conversion product and a Hcy co-substrate conversion product; and assessing the Hcy co-substrate conversion product to determine the presence, absence and/or amount of the Hcy in the sample. The Hcy co-substrate conversion product may be assessed directly, or it may be assessed by further conversion of the Hcy co-substrate conversion product into another material by the action of one or more additional enzymes. A kit for assaying homocysteine based on the same principle is also provided.

Abstract: This invention relates generally to the field of homocysteine detection. In particular, the invention provides a method for determining homocysteine presence or concentration in samples, which method comprises: contacting a sample containing or suspected of containing Hcy with a Hcy co-substrate and a Hcy converting enzyme in a Hcy conversion reaction to form a Hcy conversion product and a Hcy co-substrate conversion product; and assessing the Hcy co-substrate conversion product to determine the presence, absence and/or amount of the Hcy in the sample. The Hcy co-substrate conversion product may be assessed directly, or it may be assessed by further conversion of the Hcy co-substrate conversion product into another material by the action of one or more additional enzymes. A kit for assaying homocysteine based on the same principle is also provided.

Abstract: The present invention provides a method for assaying myeloperoxidase activity. In the assay, a sample containing myeloperoxidase or suspected of containing myeloperoxidase is contacted with substrate including serine, hydrogen peroxide, and a halide. If myeloperoxidase is present in the sample, serine is converted into glycolaldehyde, which is further converted into glycolate by a glycoaldehyde converting enzyme. The method then utilizes a cycling reaction system between glycolate and glyoxylate to generate a detectable signal that corresponds to the myeloperoxidase activity. Kits for assaying myeloperoxidases based on the same principle are also provided.

Abstract: The present invention provides a method for assaying myeloperoxidase activity. In the assay, a sample containing myeloperoxidase or suspected of containing myeloperoxidase is contacted with substrate including serine, hydrogen peroxide, and a halide. If myeloperoxidase is present in the sample, serine is converted into glycolaldehyde, which is further converted into glycolate by a glycoaldehyde converting enzyme. The method then utilizes a cycling reaction system between glycolate and glyoxylate to generate a detectable signal that corresponds to the myeloperoxidase activity. Kits for assaying myeloperoxidases based on the same principle are also provided.

Abstract: This invention relates generally to the field of homocysteine detection. In particular, the invention provides a method for determining homocysteine presence or concentration in samples, which method comprises: contacting a sample containing or suspected of containing Hcy with a Hcy co-substrate and a Hcy converting enzyme in a Hcy conversion reaction to form a Hcy conversion product and a Hcy co-substrate conversion product; and assessing the Hcy co-substrate conversion product to determine the presence, absence and/or amount of the Hcy in the sample. A kit for assaying homocysteine based on the same principle is also provided.

Abstract: This invention relates generally to the field of homocysteine detection. In particular, the invention provides a method for determining homocysteine presence or concentration in samples, which method comprises: contacting a sample containing or suspected of containing Hcy with a Hcy co-substrate and a Hcy converting enzyme in a Hcy conversion reaction to form a Hcy conversion product and a Hcy co-substrate conversion product; and assessing the Hcy co-substrate conversion product to determine the presence, absence and/or amount of the Hcy in the sample. A kit for assaying homocysteine based on the same principle is also provided.

Abstract: The present invention provides a method for assaying myeloperoxidase activity. In the assay, a sample containing myeloperoxidase or suspected of containing myeloperoxidase is contacted with substrate including serine, hydrogen peroxide, and a halide. If myeloperoxidase is present in the sample, serine is converted into glycolaldehyde, which is further converted into glycolate by a glycoaldehyde converting enzyme. The method then utilizes a cycling reaction system between glycolate and glyoxylate to generate a detectable signal that corresponds to the myeloperoxidase activity. Kits for assaying myeloperoxidases based on the same principle are also provided.

Abstract: This invention relates generally to the field of homocysteine detection. In particular, the invention provides a method for determining homocysteine presence or concentration in samples, which method comprises: contacting a sample containing or suspected of containing Hcy with a Hcy co-substrate and a Hcy converting enzyme in a Hcy conversion reaction to form a Hcy conversion product and a Hcy co-substrate conversion product; and assessing the Hcy co-substrate conversion product to determine the presence, absence and/or amount of the Hcy in the sample. A kit for assaying homocysteine based on the same principle is also provided.