Lignin derived nanoparticle intercalation on nitrogen-doped graphene quantum dots for electrochemical sensing of cardiac biomarker

• Main Authors: Vasudevan, M., Remesh, S., Perumal, V., Raja, P.B., Ibrahim, M.N.M., Gopinath, S.C.B., Lee, H.-L., Karuppanan, S., Ovinis, M., Arumugam, N., Kumar, R.S.
• Format: Article
• Published: Elsevier Inc. 2023
• Online Access: http://scholars.utp.edu.my/id/eprint/37265/; https://www.scopus.com/inward/record.uri?eid=2-s2.0-85172194275&doi=10.1016%2fj.microc.2023.109405&partnerID=40&md5=ccc32a0f5b697b8ac27c9a8045f69d24

Lignin-scribed graphene (LSG) conjugated with nitrogen-doped graphene quantum dots (N-GQDs) and lignin-derived silver nanoparticles (Ag NPs) was developed through a hydrothermal process for the electrochemical sensing of Troponin I, a cardiac biomarker for Acute Myocardial Infarction (AMI). A nanocomposite with optimal conduction mechanism was developed by varying the N-GQDs doped amount intercalated on the surface of LSG. The nanocomposite was characterised by morphological, physical, and structural examinations. The Ag NPs and N-GQDs were found uniformly distributed on the LSG surface, with selective capture of the biotinylated aptamer probe on the bio-electrode indicative of the specific interaction with Troponin I, resulting in an increment in the charge transfer resistance following hybridisation analysis. The detection limit, as determined through impedance spectroscopy, was 1 fM or 30 fg/mL, with high levels of linearity, selectivity, repeatability, and stability of the sensor. This nanocomposite opens a new avenue for array-based medical diagnostics. © 2023