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

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.

Automated summary

Plasmonic colorimetric sensors are powerful analytical tools due to their localized surface plasmon resonance extinction. In this study, NAD(P)/NAD(P)H was used as redox agents in enzymatic plasmonic gold nanostar assays to quantify galactose. The presence of galactose was detected spectrophotometrically and by the naked eye.