Impedimetric immunosensor for microalbuminuria based on a WS.sub.2/Au water-phase assembled nanocomposite

• Published in: Mikrochimica acta (1966) 2023-08, Vol.190 (8)
• Main Authors: Silveri, Filippo, Oborilová, Radka, Mácala, Jakub, Compagnone, Dario, Skládal, Petr
• Format: Article
• Language: English
• Subjects: Albumin; Atomic force microscopy; Crosslinked polymers; Detectors; Electron transport; Raman spectroscopy
• ISSN: 0026-3672
• DOI: 10.1007/s00604-023-05873-1

An electrochemical impedimetric biosensor for human serum albumin (HSA) determination is proposed. The biosensor is based on water-phase assembled nanocomposites made of 2D WS.sub.2 nanoflakes and Au nanoparticles (AuNPs). The WS.sub.2 has been produced using a liquid-phase exfoliation strategy assisted by sodium cholate, obtaining a water-stable suspension that allowed the straightforward decoration with AuNPs directly in the aqueous phase. The resulting WS.sub.2/Au nanocomposite has been characterized by atomic force microscopy and Raman spectroscopy and, then, employed to modify screen-printed electrodes. Good electron-transfer features have been achieved. An electrochemical immunosensing platform has been assembled exploiting cysteamine-glutaraldehyde covalent chemistry for antibody (Ab) immobilization. The resulting immunosensor exhibited good sensitivity for HSA detection (LOD = 2 ng mL.sup.-1), with extended linear range (0.005 - 100 [micro]g mL.sup.-1), providing a useful analytical tool for HSA determination in urine at relevant clinical ranges for microalbuminuria screening. The HSA quantification in human urine samples resulted in recoveries from 91.8 to 112.4% and was also reproducible (RSD < 7.5%, n = 3), with marked selectivity. This nanocomposite, thanks to the reliable performance and the ease of the assembling strategy, is a promising alternative for electrochemical immunosensing of health relevant markers. Graphical