detecting IL-6 for COVID, using surface coating which repel other molecule.

When COVID-19 attacks, the immune system produces a cytokine, or protein, called Interleukin-6 (IL-6), whose concentrations can offer vital information about a patient's level and stage of infection.

But measuring the critical marker has been extremely challenging, given its nearly undetectable presence in the biological stew that makes up human blood. Existing technology has not been accurate or sensitive enough to measure concentrations of IL-6 well enough to be reliable, especially in low concentrations.

researchers at McMaster University and SQI Diagnostics have created a surface that repels every other element of human blood except the critical cytokine,

The innovative surface coating is made to repel every component of blood and other complex fluids such as urine, but is dotted with microscopic islands of molecules that attract IL-6, making it possible to detect and measure IL-6 with unprecedented accuracy and sensitivity, at concentrations as low as 0.5 picograms per mL

"There are so many possibilities for these smart surfaces. We can create them to repel everything, or we can design them to interact in many beneficial ways," Didar says. "Here, we're looking for something, and only that one thing, and this allows us to separate it from everything else in a very complex environment."

Schematic representation of the process for producing PMMA‐based antibody embedded lubricant‐infused sensors for IL‐6 detection. During the microcontact printing, he IL‐6 capture antibody can crosslink to the surface through the reaction between one of the hydroxyls at the head groups of the conjugated epoxy‐based silane and the hydroxyl groups remaining after the incomplete FS treatment of the surface (red dash circles).

e) blue line: human plasma, red line: buffer

reference

Amid Shakeri et al. Antibody Micropatterned Lubricant‐Infused Biosensors Enable Sub‐Picogram Immunofluorescence Detection of Interleukin 6 in Human Whole Plasma, Small (2020). DOI: 10.1002/smll.202003844