Optimization of the Composition of NiFe-PBA Nanomaterials and Synergistic Enhancement of Electrochemiluminescence from Gold Nanoclusters via Pleated Ce-MOF: A New Strategy for S100B Immunoassay

Abstract

As a blood biomarker associated with cerebral infarction (CI), the ultrasensitive detection of S100 calcium-binding protein B (S100B) is of great significance for the early warning of CI. Electrochemiluminescence (ECL) technology holds tremendous application potential due to its high sensitivity and low background noise. However, the further expansion of ECL applications is often limited by low efficiency. In particular, gold nanoclusters (NCs) typically undergo significant nonradiative decay due to the vibrational and rotational motion of their ligands. Regulating the metal-organic frameworks structure and synergistically enhancing it with coreactant accelerators is an effective strategy to overcome this performance bottleneck. In this study, we constructed an ECL system with dual enhancement effects of emitter and coreactant sides. At the emitter side, bovine serum albumin (BSA)-stabilized AuNCs (BSA-AuNCs) were loaded onto pleated Ce-MOF (B-AuNCs/Ce-MOF), and nonradiative decay was suppressed through the rigidification effect, resulting in 1.73 times the ECL efficiency of BSA-AuNCs. At the coreactant side, NiFe-PBA nanomaterials (Ni/Fe precursor molar ratio of 3:2) were engineered to serve as coreactant accelerators. Density functional theory (DFT) calculations indicated that the model constructed with a Ni/Fe precursor ratio of 3:2 exhibited the most favorable adsorption energy of TEA, with an adsorption energy of –0.432 eV. Consequently, the B-AuNCs/Ce-MOF+NiFe-PBA system exhibited 2.12 times the ECL efficiency of BSA-AuNCs. Based on this synergistically enhanced system, ultrasensitive detection of the CI biomarker S100B was achieved, with a linear range of 0.1 pg/mL–100 ng/mL and a detection limit of 0.03 pg/mL (S/N = 3). The method also demonstrated excellent stability, reproducibility and selectivity. This strategy provides a new approach for the early diagnosis and precise detection of acute CI.