Enhanced fluorescence of tetrasulfonated zinc phthalocyanine by graphene quantum dots and its application in molecular sensing/imaging

Abstract

When excited at 435 nm, tetra-sulfonate zinc phthalocyanine (ZnPcS ) emitted dual fluorescence at 495 and 702 nm. The abnormal fluorescence at 495 nm was experimentally studied and analyzed in detail for the first time. The abnormal fluorescence at 495 nm was deduced to originate from triplet-triplet (T-T) energy transfer of excited phthalocyanine ( *ZnPcS ). Furthermore, graphene quantum dots (GQDs) enhanced the 495 nm fluorescence quantum yield (Q) of ZnPcS . The fluorescence properties of ZnPcS -GQDs conjugate were retained in a cellular environment. Based on the fluorescence of ZnPcS -GQDs conjugate, we designed and prepared an Apt29/thrombin/Apt15 sandwich thrombin sensor with high specificity and affinity. This cost-saving, simple operational sensing strategy can be extended to use in sensing/imaging of other biomolecules.

Ultrastable Amine, Sulfo Cofunctionalized Graphene Quantum Dots with High Two-Photon Fluorescence for Cellular Imaging

“…Soon, zero-dimensional graphene material, graphene quantum dots (GQDs), will be extensively applied promising next-generation probes in biosensing − and bioimaging, − because of their ecofriendliness, superior photostability, and wide range of fluorescence. Over the past decades, two-photon fluorescent (TPF) probes have been extensively developed ,− due to their low background interference and weak photobleaching.…”

Impedance spectroscopic study on hybrid phthalocyanine/lead sulphide nanocomposite film

“…Similarly, the size-dependent unique opto-electronic properties of crystalline semiconductor quantum dots (QDs) typically made of chalcogenides and phosphides of II to VI metals have attracted active research attention for their applications in nanoelectronics, optics and biological sciences [4,5]. In recent years, inorganic/organic hybrid nanocomposites incorporating semiconductor quantum dots into phthalocyanine matrix have attracted considerable interest in fundamental and applied research because of their diverse fields of applications in sensors [6,7], displays [8,9], photovoltaics [10,11] and photonic devices [12,13].…”