Feasibility of NAD(P)/NAD(P)H as redox agents in enzymatic plasmonic gold nanostar assays for galactose quantification

Tozivepi Aaron Munyayi; Danielle Wingrove Mulder; Engela Helena Conradie; Barend Christiaan Vorster

doi:10.1098/rsos.230825

Feasibility of NAD(P)/NAD(P)H as redox agents in enzymatic plasmonic gold nanostar assays for galactose quantification

R Soc Open Sci. 2023 Oct 11;10(10):230825. doi: 10.1098/rsos.230825. eCollection 2023 Oct.

Authors

Tozivepi Aaron Munyayi¹, Danielle Wingrove Mulder¹, Engela Helena Conradie¹, Barend Christiaan Vorster¹

Affiliation

¹ Centre For Human Metabolomics, Department of Biochemistry, North West University Potchefstroom, 11 Hoffman Street, Potchefstroom 2531, South Africa.

Abstract

Plasmonic colorimetric sensors have emerged as powerful analytical tools in biochemistry due to their localized surface plasmon resonance extinction in the visible range. Here, we describe the feasibility of NAD(P)/NAD(P)H as redox agents in enzymatic plasmonic gold nanostar (AuNS) assays for galactose quantification using three model enzymes, GalDH, AR and GalOx, immobilized separately on polyvinylpyrrolidone-capped AuNS scaffolds. These highly specific, sensitive and selective bioassays induce the transformation of AuNS into quasi-spherical nanoparticles during the biorecognition of galactose in water and synthetic blood matrices. As a result, using our inexpensive and simple AuNS plasmon bioassays, the presence of galactose may be detected spectrophotometrically and by the naked eye.

Keywords: bioassay; biorecognition; biosensor; gold nanostars; immobilized; redox agents.