# US 2015/0177239 A1 · Long rigid spacers to enhance binding kinetics in immunoassays > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0177239 A1 - Document ID: US20150177239A1 - Status: Published application - Kind: A1 - Application number: 14/358,550 - Filed: 2012-11-13 - Published: 2015-06-25 - Earliest claimed: 2011-11-16 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: Toon Hendrik Evers; Maatje Koets - Web page: https://patentgrep.com/patent/US20150177239A1 ## CPC - G01N 33/54393: {Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding} - G01N 21/00: Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light (G01N3/00 - G01N19/00 take precedence) - G01N 21/552: Attenuated total reflection - G01N 33/54326: {Magnetic particles} - G01N 33/54353: {with ligand attached to the carrier via a chemical coupling agent (coatings G01N33/54393)} - G01N 33/54366: {Apparatus specially adapted for solid-phase testing} - G01N 33/553: Metal or metal coated - G01N 33/6887: {from muscle, cartilage or connective tissue} - G01N 33/74: involving hormones {or other non-cytokine intercellular protein regulatory factors such as growth factors, including receptors to hormones and growth factors} - G01N 2333/58: Atrial natriuretic factor complex; Atriopeptin; Atrial natriuretic peptide [ANP]; Brain natriuretic peptide [BNP, proBNP]; Cardionatrin; Cardiodilatin - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract The present invention relates to a device for detecting a target molecule within a sample comprising a sample container for the measurement of the target molecule within a sample, a first particle, wherein said first particle is functionalized with a first binding molecule capable of specifically binding to said target molecule, and a surface structure comprising a second binding molecule, wherein said surface structure covers a flat sensor or is present on a second particle, wherein said first particle is capable of binding said second binding molecule of the surface structure directly or indirectly; wherein said first and/or second binding molecule is indirectly attached to the particle surface of said first and/or second particle and/or the flat sensor surface via a long and rigid linker molecule; wherein the length and the consistency of said linker molecule is selected such as to result in an average extension length of said linker of more than 60 nm; and wherein the number of particle clusters or of bound particles is directly or inversely related to the amount of target molecules present in the sample. In a further aspect the present invention relates to a method of detecting the presence or amount of a target molecule within a sample. The present invention also describes the use of a particle according to the invention for detecting a target molecule within a sample. ## Claims ### Claim 1 A device for detecting a target molecule within a sample comprising (a) a sample container for the measurement of the target molecule within a sample, (b) a first particle, wherein said first particle is functionalized with a first binding molecule capable of specifically binding to said target molecule, and (c) a surface structure comprising a second binding molecule, wherein said surface structure covers a flat sensor or is present on a second particle, wherein said first particle is capable of binding said second binding molecule of the surface structure directly or indirectly; wherein said first and/or second binding molecule is attached to the particle surface of said first and/or second particle and/or the flat sensor surface via a long and rigid linker molecule; wherein the length and the consistency of said linker molecule is selected such as to result in an average extension length of said linker of more than 60 nm; and wherein the number of particle clusters or of bound particles is directly or inversely related to the amount of target molecules present in the sample. ### Claim 2 (depends on 1) The device of claim 1, wherein said first and/or second particle is a magnetic particle. ### Claim 3 (depends on 1) The device of claim 1, wherein the diameter of said first and/or second particle is at least about 100 nm and wherein said average extension length is at least 10% of the diameter. ### Claim 4 (depends on 1) The device of claim 1, wherein a rigid linker molecule has an average extension length of at least 20% of the contour length of said linker molecule. ### Claim 5 (depends on 1) The device of claim 1, wherein said first binding molecule is an antibody or a fragment thereof, an aptamer, a ligand, or a complementary nucleic acid. ### Claim 6 (depends on 1) The device of claim 1, wherein said linker molecule is or comprises a nucleic acid molecule or a non-biological polymer, preferably the linker molecule being or comprising a molecule selected from the group consisting of double-stranded nucleic acid molecules such as dsDNA, a PNA molecule, a PNA-DNA duplex, and an RNA-DNA duplex. ### Claim 7 (depends on 1) The device of claim 1, wherein said first particle additionally comprises a repulsive surface structure which is directly attached to the surface of said particle, wherein said repulsive surface structure covers the surface of the particle so as to result in a specific net charge and/or a steric repulsion of the particle, and wherein said repulsive surface structure conveys a pushing effect on said particles towards said sensor surface, wherein preferably the linker molecule is longer than said repulsive surface structure. ### Claim 8 (depends on 7) The device of claim 7, wherein said repulsive surface structure is a charged structure, preferably comprising a molecule selected from the group consisting of a nucleic acid molecule, such as dsDNA, PNA, a PNA-DNA duplex, an RNA-DNA duplex, a hydro-gel, and a polymer; or a steric coating. ### Claim 9 (depends on 7) The device of claim 7, wherein said linker molecule and/or said repulsive surface structure is not cleavable by DNase and/or a restriction enzyme capable of cutting a double stranded nucleic acid molecule. ### Claim 10 (depends on 1) The device of claim 1, wherein said linker molecule further comprises at least one short flexible spacer, preferably a short flexible spacer comprising single stranded nucleic acid. ### Claim 11 (depends on 1) Method of detecting the presence or amount of a target molecule within a sample comprising the steps of (a) contacting the sample and a first binding molecule attached to a first particle in a device according to claim 1, and (b) contacting the sample with i) a second binding molecule capable of attaching to a flat surface or to a second particle, wherein the first binding molecule and/or the second binding molecule are capable of specifically binding to said target molecule, and optionally ii) a target analog molecule attached to the flat surface or to the second particle; wherein the target molecule is capable of interfering with the binding of the first binding molecule to the target analog molecule; and (c) detecting the number of first particles bound to the flat surface or to the second particle, wherein the number of particle clusters or of bound particles is directly or inversely related to the amount of target molecules present in the sample. ### Claim 12 (depends on 11) The method of claim 11, wherein a magnetic force is applied to bring the particles into close proximity with said solid support or to each other so as to facilitate clustering of the particles. ### Claim 13 (depends on 11) The method of claim 11, wherein the attachment of said second binding molecule to the flat surface or the second particle occurs prior or after the binding of the second binding molecule to the target molecule. ### Claim 14 (depends on 1) Use of a particle as defined in claim 1 for detecting a target molecule within a sample. ### Claim 15 (depends on 1) The device of claim 1, wherein said target molecule is cardiac troponin I (cTnI), NT-proBNP or parathyroid hormone.