Provided herein is a device for conducting a non-invasive diagnostic test in a subject suspected of suffering brain injury. The device for diagnosing a brain injury in a subject includes a probe of a porous matrix, an indicator formulation disposed on the porous matrix and comprises at least one lectin and/or antibody capable of selectively binding to a glycan-based biomarker indicative of brain injury in a sample, and a visually detectable label; and a handle in communication with the probe, wherein at least one of the lectin and/or antibody and/or the visually detectable label is immobilized in and/or on a detection zone in the porous matrix, and the visually detectable label develops a color intensity level and becomes visible upon a binding event of the glycan-based biomarker to the lectin and/or antibody. Also provided is a method for using the device described below and methods for producing the same.