Porous graphitic carbon nitrides integrated biosensor for sensitive detection of cardiac troponin I

Walaa Khushaim, Karthik Peramaiah, Tutku Beduk, Mani Teja Vijjapu, José Ilton de Oliveira Filho, Kuo Wei Huang, Veerappan Mani*, Khaled Nabil Salama*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

Early diagnosis of cardiovascular diseases (CVDs) has the potential to save millions of lives each year. Sensitive quantitative measurement of blood cardiac troponin I (cTnI) is required for early diagnosis of CVDs. Porous graphitic carbon nitride (PCN) nanomaterials integrated biosensor that detects picogram/mL concentrations of cTnI is reported. PCN is an updated version of graphitic carbon nitride (GCN) with improved porosity and electronic structure. A rapid two-step chemical method was described to synthesize PCN and gold nanoparticles functionalized PCN (PCN-AuNPs). The modification of the electrode surface with PCN materials had a significant impact on the electrochemically active surface area (EASA), interfacial electron transport, aptamer immobilization, and biosensing performance. The use of PCN nanomaterial in cTnI aptasensing resulted in a 3.2-fold increase in signal amplification. PCN-AuNPs found practically applicable in human blood serum (cTnI-spiked). Furthermore, a low-cost and user-friendly sensing platform has been demonstrated by integrating a PCN-AuNPs aptasensor, a custom-made miniaturized potentiostat, and a smartphone, which provided rapid, sensitive point-of-care (PoC) analysis of cTnI. Highly sensitive detection limit (0.01 pg/mL), rapid analysis time (2 min), and small sample volume (20 μL) are the other advantages of this nano-biosensor.

Original languageEnglish (US)
Article number100234
JournalBiosensors and Bioelectronics: X
Volume12
DOIs
StatePublished - Dec 2022

Bibliographical note

Funding Information:
We acknowledge the financial support from King Abdullah University of Science and Technology (KAUST) , Thuwal, Saudi Arabia. In addition, we acknowledge the funding from the KAUST smart health initiative.

Funding Information:
Next, XPS analysis was conducted to understand the chemical aspects of the material. The XPS binding energy peaks of PCN are located at 398.2, 398.9, 399.8, and 400.8 eV corresponding to sp2 hybridized –C–N[dbnd]C, tertiary N (N– (C)3), –C–N–H, and C–N bonds of PCN, respectively (Fig. 2G) (Peramaiah et al., 2021). The deconvoluted spectra displayed high-resolution information about the bonding of N and C (Fig. 2H and I). N-defective sites were estimated from survey scan XPS spectrum by calculating C/N elemental ratio. For PCN, the C/N elemental ratio was found to be 0.79, which is relatively higher than the pristine GCN. The increase in defect sites is apparently due to the creation of porous spots on the sheets. The XPS of PCN-AuNPs retained all of the distinctive peaks of PCN, with a minor shift toward high energy (Fig. 2J-M). This observation suggests that the Au nanoparticles were successfully loading onto the PCN sheets, which triggers the local electron density variation in PCN, leading to the donation of electrons from PCN to Au. With PCN-AuNPs, the C/N ratio was increased to 0.89, indicating the development of excessive N-defective sites in the presence of Au. Next, electrochemical behavior of PCN and PCN-AuNPs materials have been analyzed (Fig. 2N). CVs of PCN and PCN-AuNPs modified LSGEs have been conducted at a potential range of -0.40 V to +1.20 V with 0.1 M PBS (pH 7.40) as a supporting electrolyte. PCN modified LSGE has not shown any notable signals. A notable anodic signal was observed for PCN-AuNPs modified electrodes at +0.95 V, which is due to the oxidation of gold nanoparticles. In addition, a cathodic peak was observed at 0.10 V, which is due to the cathodic reduction of gold oxide and the electrochemical behavior of AuNPs are consistent with previous reports (Devasenathipathy et al., 2014; Ponnusamy et al., 2014). The voltammograms are stable for continuous cycles indicating the good adherence of the materials to the electrodes surface.We acknowledge the financial support from King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia. In addition, we acknowledge the funding from the KAUST smart health initiative.

Publisher Copyright:
© 2022 The Authors

Keywords

  • 2D materials
  • Acute myocardial infarction
  • Biosensors
  • Carbon nitride
  • Cardiovascular disease
  • Electrochemical

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry

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