Spatial Confinement-Enhanced Electrochemiluminescence of Gold Nanoclusters on 3D Porous ZrO2 Hollow Nanospheres for the Assessment of Acute Myocardial Infarction Protein Markers

Abstract

Herein, the gold nanoclusters@three-dimensional (3D) porous ZrO₂ hollow nanospheres (Au NCs@ZrO₂) with spatial confinement-enhanced electrochemiluminescence (SCE-ECL) were first prepared to fabricate a biosensing platform for the ultrasensitive detection of insulin-like growth factor 1 (IGF-1), which was associated with cardiovascular disease, malignant tumor, and neuropathic pain. Specifically, the confinement of Au NCs in a 3D microenvironment significantly boosted the optical radiation of excited Au NCs because the vibration of ligand molecules was restricted, and the recombination of holes and electrons of excited Au NCs was facilitated in the optical process for enhancing ECL efficiency, resulting in 5.1-fold stronger ECL efficiency than Au NCs. As a proof of concept, based on Au NCs@ZrO₂ as an emitter and an orderly and localized catalytic hairpin self-assembly (OL-CHA) system as a signal amplifier, the built ECL biosensing platform achieved fast and trace determination of IGF-1 with the detection limit (LOD) down to 0.36 fg/mL. Moreover, the ECL platform realized the assessment of the IGF-1 expression of acute myocardial infarction (AMI) patients and exhibited a more prominent accuracy than the enzyme-linked immunosorbent assay (ELISA). This work proposed a neoteric avenue for developing highly efficient ECL emitters, which presented a promising prospect in ultrasensitive bioanalysis for early diagnosis of diseases.