Microchip immunoassays for monitoring renal function: Rapid, low‐cost, and highly sensitive quantification of urinary biomarkers of diabetic nephropathy

This study developed low‐cost and highly sensitive immunoassay devices possessing the ability to rapidly analyze urine samples. Further, they can quantitatively detect three biomarkers indicating renal injury: monocyte chemotactic protein 1 (MCP‐1), angiotensinogen (AGT), and liver-type fatty acid binding protein (L‐FABP). The devices were used to successfully estimate the concentrations of the three biomarkers in urine samples within 2 min; the results were consistent with those obtained via conventional enzyme‐linked immunosorbent assay (ELISA), which requires several hours. In addition, the estimated detection limits for the three biomarkers were comparable to those of commercially available ELISA kits. Thus, the proposed and fabricated devices facilitate high‐precision and frequent monitoring of renal function.