Zeolite Nanoreactor Boosted Early Diagnosis of Acute Kidney Injury through a Multifunctional Biosensing Platform

Urinalysis plays a crucial role in the early clinical diagnosis of acute kidney injury (AKI). However, early-stage biomarker concentrations are at relatively low levels, and existing methods are limited by single-mode signal output, resulting in insufficient detection accuracy for early diagnosis. To address this, a zeolite nanoreactor-assisted electrochemiluminescence (ECL) and colorimetric sensing platform is developed for kidney injury molecule-1 (KIM-1) detection, a well-established urinary biomarker of AKI, with high sensitivity and specificity. After specific capture of KIM-1 by the antibody, the zeolite nanoreactor served as a high-capacity porous carrier for Ru(Bpy)32+ or horseradish peroxidase, which provides a nanoconfined environment to enhance ECL and colorimetric reactions, respectively. The multifunctional biosensing platform achieves dual signal output via ECL and colorimetric reactions, ranging from 0.01 pg mL−1 to 100 pg mL−1. The detection limits of KIM-1 via ECL and colorimetric analysis are 7.4 fg mL−1 and 1.0 fg mL−1, respectively. To further validate its application in a complicated environment, urine samples from drug-induced AKI mice were analyzed. The results show that both ECL and colorimetric analysis enable AKI diagnosis 6 h after drug induction, demonstrating the potential for non-invasive diagnosis in the early stages of AKI.