An organic fluorophore-nanodiamond hybrid sensor for photostable imaging and orthogonal, on-demand biosensing

Abstract

Organic fluorescent probes are widely used to detect key biomolecules; however, they often lack the photostability required for extended intracellular imaging. Here we report a new hybrid nanomaterial (peroxynanosensor, PNS), consisting of an organic fluorescent probe bound to a nanodiamond, that overcomes this limitation to allow concurrent and extended cell-based imaging of the nanodiamond and ratiometric detection of hydrogen peroxide. Far-red fluorescence of the nanodiamond offers continuous monitoring without photobleaching, while the green fluorescence of the organic fluorescent probe attached to the nanodiamond surface detects hydrogen peroxide on demand. PNS detects basal production of hydrogen peroxide within M1 polarised macrophages and does not affect macrophage growth during prolonged co-incubation. This nanosensor can be used for extended bio-imaging not previously possible with an organic fluorescent probe, and is spectrally compatible with both Hoechst 33342 and MitoTracker Orange stains for hyperspectral imaging.

Quantum monitoring of cellular metabolic activities in single mitochondria

“…Thus, new methods assessing ROS can contribute to our understanding of radical production at the nanoscale level (15,16). Fluorescent nanodiamonds (FNDs) are a very promising tool for use in the biomedical fields because of their outstanding photostability (17,18) and biocompatibility (19)(20)(21)(22)(23)(24)(25)(26). FNDs enter cells in vesicles via clathrin-mediated endocytosis or macropinocytosis (27,28).…”

Advances in the Surface Functionalization of Nanodiamonds for Biological Applications: A Review

“…These sensors are engineered from amine-functionalized HPHT NDs coupled to an organic fluorescent probe (carboxy-PF1) in the presence of NHS and EDC (Figure 3, 10). 104 By employment of NDs with intrinsic NV color centers, the FND sensors could be imaged, tracked, and read out for extended periods of time within a biological setting without any photobleaching of the carboxy-PF1 probe. Classic NHS/EDC coupling methodology was used to prepare DND-Gd(III) aggregates for potential applications as magnetic resonance imaging (MRI) contrast agents (Figure 3, 11).…”

“…For instance, novel peroxynanosensors for the detection of H 2 O 2 have recently been reported. These sensors are engineered from amine-functionalized HPHT NDs coupled to an organic fluorescent probe (carboxy-PF1) in the presence of NHS and EDC (Figure , 10 ) . By employment of NDs with intrinsic NV color centers, the FND sensors could be imaged, tracked, and read out for extended periods of time within a biological setting without any photobleaching of the carboxy-PF1 probe.…”

Nanomaterials for Healthcare Biosensing Applications

“…A broad spectrum of compounds that find applications in healthcare diagnosis and POC analysis of diseases can be detected with such biosensor materials [22]. Carbon allotrope-based nanomaterials consisting of fullerenes, [23,24,25,26,27] nanotubes (CNT) [28,29,30,31,32,33], films of graphene and its derivatives [34,35,36,37], quantum dots [38,39,40,41], and nanodiamonds [42,43,44,45,46,47] play a substantial role in recent advancements in the biosensor domain. In addition to greater sensitivity and novel mechanisms, such sensors offer a higher spatial resolution in case of localised detection along with real-time and label-free non-destructive sensing.…”