HEPATOSENSE: GRADING LIVER DAMAGE BIOSENSOR SECTION 1: ABSTRACT Chronic liver disease affects an estimated 1.5 billion people worldwide, yet the tools available to detect and stage it remain either too invasive, too expensive, or too dependent on hospital infrastructure to be used preventatively at scale. The current gold standard for liver damage diagnosis is inaccessible in most low- and middle-income settings, and simpler serum enzyme tests like ALT and AST provide only a coarse result that doesnt distinguish the grade of the liver damage. This diagnostic gap allows millions of patients to progress silently from Grade 1 liver stress, which is fully reversible through lifestyle intervention, to Grade 3 fibrosis, which is not simply because no affordable graded diagnostic tool exists at the point of care. The overall goal of HepatoSense is to develop a multi-channel, paper-based synthetic biology diagnostic that grades liver injury severity across five clinical stages, from healthy to fibrotic, using a panel of seven biomarkers detectable directly from a serum sample, without laboratory equipment or cold chain requirements.