EGFR antibody conjugated bimetallic Au@Ag nanorods for enhanced SERS-based tumor boundary identification, targeted photoacoustic imaging and photothermal therapy

The development of multifunctional nanoprobes for simultaneous targeted imaging, tumor boundary identification and photothermal therapy of gastric cancer has become a great challenge. Herein, EGFR monoclonal antibody-conjugated Au@Ag nanorods decorated with DTNB nanoprobes (5,5'-Dithiobis-(2-nitrobenzoic acid)) (EGFR-Au@Ag NR nanotags) were prepared and characterized. Their biocompatibility was analyzed by MTT assay. In vitro studies show that EGFR-Au@Ag NR nanotags own good biocompatibility and capability of targeting and entering into gastric cancer MGC803 cells, silver nano-film layer on the surface of gold nanorods remarkably enhance surfaceenhanced rama spectra (SERS) signal, enhanced photoacoustic imaging efficacy and photothermal conversion efficiency of gold nanorods. In vivo studies show that prepared nanotags could target actively gastric cancer cells at 2 h post-injection, and distributed in the tumor site, exhibited enhanced SERS signals to display clearly tumor boundary, enhanced photoacoustic imaging to display clearly tumor boundary. Under 1 w/cm² laser irradiation, tumor growth was remarkably inhibited by local photothermal therapy. In conclusion, high performance EGFR-antibody conjugated Au@Ag nanorod- DTNB nanoprobes exhibit great potential in applications such as targeted photoacoustic imaging, simultaneous tumor boundary identification and selective photothermal therapy of gastric cancer in the near future.