Quantitative Galactose Colorimetric Competitive Assay Based on Galactose Dehydrogenase and Plasmonic Gold Nanostars.
Tozivepi Aaron MunyayiDanielle Wingrove MulderEngela Helena ConradieFrans Johannes SmitBarend Christiaan VorsterPublished in: Biosensors (2023)
We describe a competitive colorimetric assay that enables rapid and sensitive detection of galactose and reduced nicotinamide adenine dinucleotide (NADH) via colorimetric readouts and demonstrate its usefulness for monitoring NAD+-driven enzymatic reactions. We present a sensitive plasmonic sensing approach for assessing galactose concentration and the presence of NADH using galactose dehydrogenase-immobilized gold nanostars (AuNS-PVP-GalDH). The AuNS-PVP-GalDH assay remains turquoise blue in the absence of galactose and NADH; however, as galactose and NADH concentrations grow, the reaction well color changes to a characteristic red color in the presence of an alkaline environment and a metal ion catalyst (detection solution). As a result, when galactose is sensed in the presence of H 2 O 2 , the colored response of the AuNS-PVP-GalDH assay transforms from turquoise blue to light pink, and then to wine red in a concentration-dependent manner discernible to the human eye. This competitive AuNS-PVP-GalDH assay could be a viable analytical tool for rapid and convenient galactose quantification in resource-limited areas.
Keyphrases
- sensitive detection
- loop mediated isothermal amplification
- high throughput
- gold nanoparticles
- hydrogen peroxide
- quantum dots
- endothelial cells
- fluorescent probe
- label free
- nitric oxide
- room temperature
- single molecule
- liquid chromatography
- pluripotent stem cells
- reduced graphene oxide
- silver nanoparticles
- real time pcr