Ratiometric fluorescence detection of tetracycline for tetracycline adjuvant screening in bacteria

• Published in: Sensors and actuators. B, Chemical Chemical, 2022-12, Vol.372, p.132687, Article 132687
• Main Authors: Zhang, Shangqing, Sun, Qixuan, Liu, Xun, Li, Haiyan, Wang, Jianhua, Chen, Mingli
• Format: Article
• Language: English
• Subjects: Adenine; Adjuvants; Bacteria; Carbon nitride; E coli; Europium; Flow resistance; Fluorescence; Public health; Screening
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2022.132687

Persistent generation of tetracycline (TC) resistant bacteria poses serious risks for public health. It is of great importance to develop a strategy for rapid screening TC adjuvants for restore TC-susceptibility against resistant bacteria. Herein, a flower-like europium-doped nanoprobe is created by coordinating Eu3+ with adenine (Ade)-graphitic carbon nitride (g-C3N4) conjugate (g-C3N4-Ade-Eu). TC quenches the intrinsic fluorescence of g-C3N4 at 436 nm via internal filter effect (IFE), and meanwhile the antenna effect (AE) of TC significantly promotes the emission of Eu3+ at 618 nm. These fluorescence responsive behaviors of g-C3N4-Ade-Eu ensure ratiometric fluorescence assay of TC within 0.01 − 10 μM, along with a limit of detection (LOD) of 5.0 nM. The nanoflower structure exhibits large surface area, which endows enrichment of TC on the flower surface to ensure a high assay sensitivity. Tetracycline in bacteria is quantified for the first time by this protocol, and it further facilitates the rapid screening (∼3 h) of tetracycline adjuvants in E.coli ER2738.