Gold nanoprisms as a hybrid in vivo cancer theranostic platform for in situ photoacoustic imaging, angiography, and localized hyperthermia

The development of high-resolution nanosized photoacoustic contrast agents is an exciting yet challenging technological advance. Herein, antibody （breast cancer-associated antigen I （Brcaal） monoclonal antibody）- and peptide （RGD）- functionalized gold nanoprisms （AuNprs） were used as a combinatorial methodology for in situ photoacoustic imaging, angiography, and localized hyperthermia using orthotopic and subcutaneous murine gastric carcinoma models. RGD-conjugated PEGylated AuNprs are available for tumor angiography, and Brcaal monodonal antibody-conjugated PEGylated AuNprs are used for targeting and for in situ imaging of gastric carcinoma in orthotopic tumor models. In situ photoacoustic imaging allowed for anatomical and functional imaging at the tumor site. In vivo tumor angiography imaging showed enhancement of the photoacoustic signal in a time-dependent manner. Furthermore, photoacoustic imaging demonstrated that tumor vessels were clearly damaged after localized hyperthermia. This is the first proof-of-concept using two AuNprs probes as highly sensitive contrasts and therapeutic agents for in situ tumor detection and inhibition. These smart antibody/peptide AuNprs can be used as an efficient nanotheranostic platform for in vivo tumor detection with high sensitivity, as well as for tumor targeting therapy which, with a single-dose injection, results in tumor size reduction and increases mice survival after localized hyperthermia treatment.

Multifunctional shape-dependent plasmonic nanoprobe by enzymatic etching of single gold triangular nanoplate

Hydrogen peroxide(H2O2),as a signaling molecule,plays a vital role in a wide variety of signaling transduction processes,aging,and diseases.However,the excessive production of H2O2 causes various diseases.Herein,we develop a novel method for H2O2 detection in live cells via dark-field scattering spectroscopy with gold triangular nanoprisms(AuTNPs)as probes.The corners of AuTNPs would be gradually oxidatively etched by the strong coordination of Br•which is generated by enzymatic reactions in the presence of horseradish peroxidase(HRP),bromide ion and trace hydrogen peroxide.Benefitting from the morphological change,the single AuTNP based plasmonic nanoprobe shows notable blueshifts and scattering color changes which could be real-time monitored under the dark-field microscopy.The peak position in the scattering spectra of individual AuTNP blueshifts linearly with the increase of H2O2 concentration,and exhibits high sensitivity to H2O2 in a large range from 2.5 to 100µM with a low detection limit(LOD)of 0.74µM.Moreover,the experimental results were supported by the simulated results via the finite-difference time-domain(FDTD)method.The nanoprobes have been further used for intracellular H2O2 detection in live cells.Besides,the etching of AuTNP also provides an alternative method to design novel plasmonic logic chips and write-once plasmonic memories.