Construction and mechanism analysis of an ultra-sensitive GCN/Pb2+/PPy heterojunction electrochemiluminescent sensor for detecting Cu(ii)

Abstract

A highly stable electrochemiluminescent (ECL) sensor based on graphitic carbon nitride (GCN)/Pb²⁺/polypyrrole (PPy) was developed to detect trace copper ions. The hydrochloric acid immersion technique was applied to rearrange PPy chains for the first time. Under optimal experimental conditions, the ECL intensity increased linearly with the increase of Cu²⁺ concentration in solution from 10⁻¹² M to 10⁻⁶ M (1 pM to 1 μM), with a super low limit of detection (LOD) of 10⁻¹² M (1 pM) (S/N = 3). Additionally, the impact of detection on the localized states of the composite nanomaterial was revealed by applying Vienna ab initio Simulation Package (VASP) and Gaussian 16.