An amplified voltammetric immunosensor for detection of porcine serum albumin using a self-standing nanohybrid composed of multi-walled carbon nanotubes, polyelectrolytes, and gold nanoparticles

• Published in: MICROCHEMICAL JOURNAL
• Main Authors: Mahmud, Abdul Hadi; Gati, Nor Izzati; Jani, Abdul Mutalib Md; Abu Bakar, Noor Fitrah; Abidin, Siti Aimi Sarah Zainal; Zain, Zainiharyati Mohd; Low, Kim-Fatt
• Format: Article
• Language: English
• Published: ELSEVIER 2024
• Subjects: Chemistry
• Online Access: https://www-webofscience-com.uitm.idm.oclc.org/wos/woscc/full-record/WOS:001338899700001
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2024.111928

Here, we introduce an innovative approach for signal amplification of a voltammetric immunosensor platform with nanoporous alumina (NPA) millirods to specifically target porcine serum albumin (PSA). A self-standing nanohybrid was constructed using a layer-by-layer assembly technique, which involved coating multi-walled carbon nanotube (MWCNTs) with polyelectrolytes (PEs) and subsequent attachment of multiple gold nano- particles (AuNPs). The PEs improved dispersion of the MWCNTs and facilitated attachment to multiple AuNPs for enhanced bioconjugation with anti-PSA detection (alpha-PSAD) antibodies. The morphology of the nanohybrid was examined using field-emission scanning electron microscopy. The resulting MWCNT/PE/AuNP/alpha-PSAD-bioconjugated nanohybrid acted as an amplified signaling probe for the PSA-specific, NPA millirod-based voltammetric immunosensor. A current value recorded at +0.68 V (vs. Ag/AgCl reference electrode) in the voltammogram served as the analytical signal for quantification, thereby eliminating the need to analyze peak characteristics. Demonstrating remarkable sensitivity, the nanohybrid achieved a PSA detection limit of 0.5 pg/ mL, surpassing the 50 pg/mL limit of an immunosensor using a single AuNP for signaling. The proposed nanohybrid offers a superior solution for highly sensitive detection of PSA in voltammetric immunosensor applications.