Abstract: A device and system for conducting accurate diagnosis of states of disease or health, including cancer, with high sensitivity and specificity is described. The system employs a portable cassette-based testing system which is configured to detect pp analytes captured by hydrogel particles equipped with affinity bait(s) and an amplification reporter system. The affinity baits bind to a wide range of analytes, including: metabolites, proteins, nucleic acids, lipids, hormones, cytokines, growth factors, biomarkers, virus particles, exosomes, bacteria, fungi, drug compounds, synthetic organic compounds, volatile odorants, toxicants, and pollutants. The affinity baits bind with extremely high affinity, preserving the captured analyte. This system can increase the sensitivity of detection of said analytes up to ten-thousand-fold.