Nitrogen, Cobalt Co-doped Fluorescent Magnetic Carbon Dots as Ratiometric Fluorescent Probes for Cholesterol and Uric Acid in Human Blood Serum

Authors

Shan Huang, Nanning Normal University & University of Nebraska-Lincoln
Erli Yang, Nanning Normal University
Jiandong Yao, Nanning Normal University
Xu Chu, Nanning Normal University
Yi Liu, Nanning Normal University
Yue Zhang, Nanning Normal University
Qi Xiao, Nanning Normal UniversityFollow

ORCID IDs

0000-0002-6133-1853

0000-0002-6140-3757

Document Type

Article

Date of this Version

5-28-2019

Citation

2019 American Chemical Society

Comments

DOI: 10.1021/acsomega.9b00874 ACS Omega 2019, 4, 9333−9342

Abstract

Detection of cholesterol and uric acid biomarkers is of great importance for clinical diagnosis of several serious diseases correlated with their variations in human blood serum. In this study, a new kind of well selective and highly sensitive ratiometric fluorescent probe for cholesterol and uric acid determination in human blood serum was innovatively developed on the basis of the inner filter effect (IFE) process of nitrogen, cobalt co-doped carbon dots (N,Co-CDs) with 2,3-diaminophenazine (DAP). DAP was the oxidative product during the oxidation reaction between ophenylenediamine and H2O2. Fluorescent magnetic N,Co-CDs possessing blue emission and magnetic property were prepared through a facile one-pot hydrothermal strategy by using citric acid, diethylenetriamine, and cobalt(II) chloride hexahydrate as precursors. N,Co-CDs exhibited good ferromagnetic property and excellent optical properties even in extremely harsh environmental conditions, implying the huge potential applications of such N,Co-CDs in biological areas. On the basis of the IFE process between N,Co-CDs and DAP, N,Co-CDs were applied to establish ratiometric fluorescent probes for the indirect detection of cholesterol and uric acid that participated in enzyme-catalyzed H2O2-generation reactions. The established IFEbased fluorescent probes exhibited relatively low detection limits of 3.6 nM for cholesterol and 3.4 nM for uric acid, respectively. The fluorescent probe was successfully utilized for the determination of cholesterol and uric acid in human blood serum with satisfying results, which provided an informed perspective on the applications of such doped CDs to explore the specific and sensitive nanoprobe in disease diagnoses and clinical therapy.