Soft scaffold aided plasmon-enhanced upconversion luminescence and its application in vascular endothelial growth factor (VEGF) detection

The dimensioning of glutathione-coated gold nanoparticles (GSH-Au NPs) greatly enhanced the luminescence intensity of upconversion nanoparticles (UCNPs) in close proximity and offered significant implications for biomedicine and materials science. According to systematic studies, the luminescence changes between UCNPs and AuNPs are enhanced by a well-tuned electric field-induced absorption, especially when the distance between the two is approximately 5 nm. At this distance, an upconversion enhancement factor of approximately 4.4 is achieved at a wavelength of 361 nm. This maximized plasmonic enhancement effect was subsequently employed for the quantification of Vascular Endothelial Growth Factor (VEGF) with the well-fabricated plasmon-enhanced luminescence complex (PELC) by replacing the ssDNA with the corresponding aptamer. This complex provides a basis for the rational design of a hybrid metal-upconversion complex to enhance luminescence for bioimaging and sensing applications.