Anisotropic growth of gold anchors on CdSe semiconductor quantum platelets for self-assembled architectures with well-connected electronic circuits for the electrochemical detection of enrofloxacin

• Published in: Analyst (London) 2024-05, Vol.149 (11), p.3131-3139
• Main Authors: Cao, Yue, Wang, Shengyan, Li, Huan, Gao, Yan-Yan, Li, Mei, Wang, Hua, Zhu, Wenlei, Zhou, Yang
• Format: Article
• Language: English
• Subjects: Cadmium selenides; Charge transfer; Chemical sensors; Circuit reliability; Electric fields; Electrochemical analysis; Electronic circuits; Energy gap; Gold; Molecular orbitals; Nanomaterials; Oxidation; Self-assembly
• ISSN: 0003-2654; 1364-5528
• DOI: 10.1039/d4an00412d

Anisotropic growth of nanomaterials enables advances in building diverse and complex architectures, which exhibit unique properties and enrich the choice of nano-building modules for electrochemical sensor devices. Herein, an anisotropic growth method was proposed to anchor gold nanoparticles (AuNPs) onto both ends of quasi-two-dimensional CdSe semiconductor quantum nanoplatelets (NPLs), appearing with a monodisperse and uniform nano-dumbbell shape. Then, these AuNPs were exploited as natural anchor points and further initiated self-assembly to create complex architectures via dithiol bridges. Detailed studies illustrated that the covalent Se-Au bonds facilitate effective charge transfer in the internal metal-semiconductor (M-S) electric field. The narrowed energy gap and up-shifted highest occupied molecular orbital were favored for electron removal during the electro-oxidation process. The ultrathin CdSe NPLs supplied a large specific surface area, carrying remaining holes and abundant active sites for target electro-catalysis. As a result, using the assembled complex as the electrode matrix with well-connected electronic circuits, a reliable electrochemical sensor was achieved for enrofloxacin detection. Under the optimal conditions, the current response exhibits two linear dynamic ranges, 0.01-10.0 μM and 10.0-250 μM, and the detection limit was calculated as 0.0026 μM. This work not only opens up broad application prospects for heterogeneous M-S combinations as effective electrochemical matrixes but also develops reliable antibiotic assays for food and environmental safety. Anisotropic growth of gold anchors on CdSe semiconductor quantum platelets for self-assembled architectures with well-connected electronic circuits for enrofloxacin electro-oxidation.