Spatially programmed MOF-coated microchannels for capillary-driven microvolume analysis
Year: 2026
Type: preprint
Abstract: Metal–organic frameworks (MOFs) and covalent organic frameworks (COFs) offer chemically and geometrically programmable pore environments that have been exploited as coatings for capillary- and fiber-based microextraction. However, most formats still rely on discrete adsorbent handling or external fluid actuation, poorly suited to the microliter sample volumes typical of biological specimens. Here we report glass microcapillaries bearing a spatially programmed, nanometer-thick MOF film that simultaneously drives fluid uptake by capillary action and performs localized analyte enrichment within a single, self-contained channel. Retaining the adsorbent as a conformal film rather than a particulate phase removes the need for separate adsorbent handling. It also concentrates chemical functionality at the fluid-contacting surface, enabling efficient enrichment from a few microliters without external pumps. We demonstrate this approach by enriching and quantifying the inflammation-associated metabolites kynurenine and quinolinic acid from microliter volumes of mouse blood serum, achieving clear discrimination between inflammatory and control conditions. These MOF-coated microcapillaries offer an integrated route to low-volume biofluid analysis in settings where sample availability and external fluid handling are limiting.
Source: ChemRxiv
Institution: Tata Institute of Fundamental Research
Language: English
Subfield: Analytical Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7220746819