Black Phosphorus Quantum Dots with Exposed (113) Planes on Chemiluminescent Luminol–K3Fe(CN)6 for Detection of Dopamine

Exploring the possible catalytic effect of black phosphorus quantum dots (BPQDs) with specific exposed planes on chemiluminescence (CL) to improve CL intensity and achieve excellent analytical performance is one of the latest research hotspots. Herein, uniform BPQDs with highly exposed (113) facets and an average size of 2.2 nm were fabricated via a facile ultrasonic exfoliation strategy. The enhanced CL intensity in the BPQDs–luminol–K3Fe(CN)6 system is attributed to the catalytic effect of BPQDs. The catalytic mechanism of BPQDs involved in luminol–K3Fe(CN)6 CL is revealed by theoretical calculations, which show an adsorption Gibbs free energy for oxygen of −0.86 eV, accompanied by the separation of electron–hole pairs (e––h+). In other words, after being irradiated by the CL generated from luminol and K3Fe(CN)6, the BPQDs effectively catalyze the decomposition of dissolved oxygen to produce superoxide radical anions, which further react with luminol to increase CL emission. The noticeable suppression of the CL signal in the presence of dopamine acquired under mild conditions makes it attractive for biosensor applications, deepening the understanding of BPQDs as efficient catalysts and promoting the potential development of BPQD-based materials in the fields of photonics, biomedicine, and electronics.