Application of Supramolecular Host-Guest Recognition in Electrochemiluminescence Protein Sensing Platform

Abstract

The utilization of antibodies to detect proteins essentially depends on the retention of binding affinity, and therefore complex strategies are required to preserve the biometric elements of antibodies. Herein we innovatively apply the supramolecular host-guest recognition strategy to construct an electrochemiluminescence (ECL) proteins sensing platform for problem solving. Supermolecule cucurbit[7]uril (CB[7]) was used to selectively capture insulin based on the inherent characteristics of protein terminals. Moreover, CB[7] rigid mercaptopropionic acid (MPA) and L-phenylalanine (L-Phe) stabilized gold nanoclusters (CB[7]/L-Phe/MPA-AuNCs) were used as luminophore of the ECL sensing platforms. The passivation of the nanocluster surface by supramolecular recognition with CB[7] restricted the non-radiative relaxation, reduced the surface energy, and significantly improved the intensity and stability of anodic ECL. The prepared ECL insulin sensing platforms exhibited a linear range from 50.00 fg/mL to 100.0 ng/mL with a detection limit of 5.44 fg/mL (S/N=3). Our study reveals the critical role of host-guest recognition in analyte recognition and signal amplification, extending the scope of supramolecular applications in ECL.

Keywords: supramolecular, host-guest recognition, protein sensing platforms, electrochemiluminescence.