Turn-Off Fluorometric Determination of Bilirubin Using Facile Synthesized Nitrogen-Doped Carbon Dots as a Fluorescent Probe

D James Nelson; N Vasimalai; S Abraham John; M G Sethuraman

doi:10.1007/s10895-023-03572-x

Turn-Off Fluorometric Determination of Bilirubin Using Facile Synthesized Nitrogen-Doped Carbon Dots as a Fluorescent Probe

J Fluoresc. 2024 Jan 13. doi: 10.1007/s10895-023-03572-x. Online ahead of print.

Authors

D James Nelson¹, N Vasimalai², S Abraham John¹, M G Sethuraman³

Affiliations

¹ Department of Chemistry, The Gandhigram Rural Institute-Deemed to Be University, Gandhigram, Dindigul, 624302, Tamilnadu, India.
² Department of Chemistry, B.S. Abdur Rahman Crescent Institute of Science and Technology, Vandalur, Chennai, 600048, Tamilnadu, India.
³ Department of Chemistry, The Gandhigram Rural Institute-Deemed to Be University, Gandhigram, Dindigul, 624302, Tamilnadu, India. mgsethu@gmail.com.

PMID: 38217780
DOI: 10.1007/s10895-023-03572-x

Abstract

Bilirubin plays a significant role in human health management, particularly in the case of jaundice. Because of the need for the monitoring of bilirubin levels in jaundice patients, the development of a robust sensitive method becomes essential. Here, we describe the development of a highly sensitive and selective turn-off fluorometric detection method for bilirubin in blood serum samples using nitrogen-doped carbon dots (N-CDs). N-CDs was synthesized by the pyrolysis process, using citric acid and L-asparagine as the carbon and nitrogen sources, respectively. The prepared N-CDs solution showed highly intense blue emission with good stability. The HR-TEM image of N-CDs revealed spherical dot-like structures with an average size calculated to be 7.16 nm. Further, the surface functional groups of N-CDs were analyzed by FT-IR, Raman, XRD, and XPS techniques. Fluorescence spectra showed the maximum emission intensity at 443 nm (λ_ex). The linear range of addition was performed from 1 to 150 µM, and the limit of detection (LOD) was determined to be 1.97 nM. The emission of N-CDs was quenched by Förster Resonance Energy Transfer (FRET) by adding bilirubin. These N-CDs showed extraordinary sensitivity and selectivity in the detection of bilirubin. Hence, this fluorescent probe has been proven successful in detecting the concentration of free bilirubin in human serum samples.

Keywords: Carbon dots; FRET; Fluorometric; Hyperbilirubinemia; Jaundice; Turn-off.