Photothermal enhanced fluorescence quenching of Tb-norfloxacin for ultrasensitive human epididymal 4 detection

• Published in: Mikrochimica acta (1966) Vol. 190; no. 3; p. 108
• Main Authors: Du, Lizhen, Chen, Yanjie, Huang, Yitian, Yan, Shanshan, Zhang, Shupei, Dai, Hong
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.03.2023; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Biomolecules; Biosensors; Carboxyl group; Carboxymethyl cellulose; Carboxymethylcellulose Sodium; Cellulose; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Coloring Agents; Coordination polymers; Detectors; Electron transfer; Electron transport; Electronegativity; Fluorescence; Humans; Immunoassay; Infrared lasers; Infrared Rays; Microengineering; Nanochemistry; Nanocomposites; Nanoparticles; Nanotechnology; Niobium carbide; Norfloxacin; Original Paper; Photothermal conversion; Quenching; Carboxymethyl cellulose; Photothermal effect; C MXene nanocomposite; Nb; Tb-Norfloxacin coordination polymer nanoparticles; Fluorescence quenching; Nb2C MXene nanocomposite
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-023-05689-z

A fluorescence quenching enhanced immunoassay has been developed to achieve ultrasensitive recognition of human epididymal 4 (HE4) modifying the fluorescence quencher. The carboxymethyl cellulose sodium-functionalized Nb 2 C MXene nanocomposite (CMC@MXene) was firstly introduced to quench the fluorescence signal of the luminophore Tb-Norfloxacin coordination polymer nanoparticles (Tb-NFX CPNPs). The Nb 2 C MXene nanocomposite as fluorescent nanoquencher inhibits the electron transfer between Tb and NFX to quench the fluorescent signal by coordinating the strongly electronegative carboxyl group on CMC with Tb (III) of Tb-NFX complex. Simultaneously, due to the superior photothermal conversion capability of CMC@MXene, the fluorescence signal has been further weakened by the photothermal effect driven non-radiative decay of the excited state under near-infrared laser irradiation. The constructed fluorescent biosensor based on CMC@MXene probe finally realized the enhanced fluorescence quenching effect, and achieved ultra-high sensitivity and selective detection of HE4, exhibiting a wide linear relationship with HE4 concentration on the logarithmic axis in the range of 10 −5 to 10 ng/mL and a low detection limit of 3.3 fg/mL (S/N = 3). This work not only provides an enhanced fluorescent signal quenching method for the detection of HE4, but also provides novel insights for the design of fluorescent sensor toward different biomolecules. Graphical Abstract