{
  "abstract": "In a crowded extracellular environment, viruses and nanoparticles must reach the cell membrane within a few nanometers before the first ligand-receptor bond can form. Crowders generate an entropic depletion attraction, yet continuum models usually assume contact is already established or treat the approach deterministically. We formulate a thermodynamically consistent stochastic theory for this pre-contact stage. The sphere-plane depletion geometry uses the exact Asakur-Oosawa spherical-cap overlap, rather than a fitted cap, with either ideal van 't Hoff or pressure-only Carnahan-Starling osmotic pressure. A spatially varying near-wall mobility introduces a noise-induced drift that is essential for thermodynamic consistency and is often omitted. The first specific reaction is modeled by a Robin radiation boundary; the outer boundary is reflecting or absorbing. Three first-passage problems are solved analytically by quadrature: the mean reaction time, the reaction-before-escape probability, and the conditional success time, the last encoded by a Doob transform that exposes the selection bias of conditioning on capture. The theory separates thermodynamic inputs from conditional parameters and reveals a reaction-limited to diffusion-limited crossover controlled by the local Damköhler number. For typical virus and nanoparticle parameters, the depletion well reaches $2$-$6\\,k_{\\rm B}T$, capture times are $0.1$-$1\\,{\\rm ms}$, and the conditional success time is measurably shorter than the unconditional mean. Finite-volume and Chebyshev schemes reproduce the analytic results within their discretization errors and satisfy the radiation-boundary mass balance. This provides a quantitative theoretical framework for crowding-assisted capture prior to membrane wrapping and a reference for comparing crowding, near-wall mobility, and surface reactivity in endocytosis.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.01321",
  "author_total": 1,
  "authors": [
    {
      "name": "Hao Wu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ataycresp0y1q.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.01321",
  "fulltext_url": null,
  "id": "ataycresp0y1q",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.01321",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.soft"
    ],
    [
      "arxiv",
      "cond-mat.stat-mech"
    ],
    [
      "arxiv",
      "physics.bio-ph"
    ],
    [
      "arxiv",
      "physics.chem-ph"
    ],
    [
      "arxiv",
      "q-bio.SC"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.01321",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-01",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ataycresp0y1q.ris",
  "sources": [
    {
      "first_seen": "2026-11-03T12:20:59Z",
      "native_id": "2611.01321",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.01321"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "arxiv:q-bio.SC",
      "subfield": "cell-biology"
    },
    {
      "field": "chemistry",
      "origin": "arxiv:physics.chem-ph",
      "subfield": "physical"
    },
    {
      "field": "physics",
      "origin": "arxiv:physics.bio-ph",
      "subfield": "biological-medical"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.soft",
      "subfield": "condensed-matter"
    },
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.stat-mech",
      "subfield": "statistical-nonlinear"
    }
  ],
  "title": "Before the First Bond: Depletion-Assisted Stochastic Capture at the Onset of Endocytosis",
  "title_text": "Before the First Bond: Depletion-Assisted Stochastic Capture at the Onset of Endocytosis",
  "type": "preprint",
  "updated_at": "2026-11-05T15:20:29Z",
  "url": "https://research.draconitic.com/paper/ataycresp0y1q",
  "venue": "arXiv",
  "versions": []
}