Magnetic structural color microspheres for the multiplex detection of acute kidney injury biomarkers.

Background: Acute kidney injury (AKI) is a frequent acute condition that features sharp loss of kidney functions and often leads to severe situations such as end-stage renal disease and even death. The incidence and mortality of AKI in hospitalized patients are high worldwide, and one of the reasons for this poor prognosis is the inability to diagnose AKI promptly. The sensitive and specific assay of biomarkers is considered a promising method for early diagnosis of AKI.

Results: We designed a magnetic-responsive structural colored inverse opal hydrogel microspheres (IOHMs) for the multiplex detection of cystatin C (CysC) and neutrophil gelatinase-associated lipocalin (NGAL), which are two early biomarkers of AKI. The microsphere possessed structural colors for encoding and directional motion ability for improved detection sensitivity and separation efficiency, showing the detection ranges of CysC and NGAL in 10-5000 ng/mL and 10-1000 ng/mL, respectively.

Significance: The method's accuracy and reliability were consistent with commonly used enzyme-linked immunosorbent assay methods. Therefore, these magnetic IOHMs have a promising application for early AKI diagnosis.