Biomedical Applications for Gold Nanoclusters: Recent Developments and Future Perspectives

Abstract

Gold nanoclusters (AuNCs) have been extensively applied as a fluorescent probe for biomedical applications in imaging, detection, and therapy due to their unique chemical and physical properties. Fluorescent probes of AuNCs have exhibited high compatibility, superior photostablility, and excellent water solubility which resulted in remarkable biomedical applications for long-term imaging, high-sensitivity detection, and target-specific treatment. Recently, great efforts have been made in the developments of AuNCs as the fluorescent probes for various biomedical applications. In this review, we have collected fluorescent AuNCs prepared by different ligands, including small molecules, polymers, and biomacromolecules, and highlighted current achievements of AuNCs in biomedical applications for imaging, detection, and therapy. According to these advances, we further provided conclusions of present challenges and future perspectives of AuNCs for fundamental investigations and practical biomedical applications.

Keywords: Biomacromolecules; Detection; Gold nanoclusters; Imaging; Polymers; Small molecules; Therapy; ligand.

Fig. 1

a Image of HeLa cells after incubation with DPA-AuNCs for 2 h by confocal microscopy. b 3D Image displaying internalized DPA-AuNCs in cross-sectioned view [55]. The colors of DPA-AuNCs and membrane dye DiD are depicted in green and red, respectively

Fig. 2

Intensity (a, c) and FLIM (b, d) images of Hela cells only (a, b) and Hela cells incubated with DHLA-AuNCs for 1 h (c, d). All scale bars are 10 μm [56]

Fig. 3

Near-infrared fluorescent try-AuNCs as surface plasmon-enhanced energy transfer biosensor and in vivo cancer imaging bioprobe [58]

Fig.4

a Fluorescence intensity of MUA-AuNCs in the absence of 170 μM Hg²⁺. b Agglomeration of Hg²⁺ with COOH group of MUA-AuNCs in the presence of 170 μM Hg²⁺. c Fluorescence intensity after 10 mM cysteine had been added to the sample in B [64]

Fig. 5

Labelling of normal and cancer cells with AuNCs and quantum dots (QDs) [79]

Fig. 6

Fabrication of L-AuNCs/FA-PDNH nanocomposite for imaging and therapy [88]

Fig. 7

Schematic of the formation of FA-Ova-AuNCs for cancer cell imaging [90]

Fig. 8

Fabrication of the Tf-AuNCs/GO conjugation as a turn-on NIR fluorescent probe for bioimaging in cancer cells with TfR over expression [94]

Fig. 9

The method for the synthesis of luminescent AuNCs by emulating the PCR condition [95]