The delineation of brain gliomas margins still poses challenges to precise imaging and targeted therapy, mainly due to strong light attenuation of the skull and high background interference. With deep penetration and high sensitivity, photoacoustic (PA) imaging (PAI) in the second near‐infrared (NIR II) window holds great potential for brain gliomas imaging. Herein, mesoionic dye A1094 encapsulated in Arg‐Gly‐Asp‐modified hepatitis B virus core protein (RGD‐HBc) is designed and synthesized for effective NIR II PAI of brain gliomas. An aggregation‐induced absorption enhancement mechanism is discovered in vitro and in vivo. It is also demonstrated that A1094@RGD‐HBc, with an enhanced absorption in the NIR II window, displays ninefold PA signal amplification in vivo, allowing for precise PAI of the brain gliomas at a depth up to 5.9 mm. In addition, with the application of abovementioned agent, high‐resolution PAI and ultrasensitive single photon emission computed tomography images of brain gliomas are acquired with accurate co‐localization. Collectively, the results suggest great promise of A1094@RGD‐HBc for diagnostic imaging and precise delineation of brain gliomas in clinical applications.

Phototheranostic technology based on photoacoustic imaging (PAI) and photothermal therapy (PTT) is emerging as a powerful tool for tumor theranostic applications. For effective tumor eradication, a novel PAI/PTT theranostic nanoagent with an excellent optical absorption and photothermal capability is highly desired. Herein, we present a new PAI/PTT nanohybrid named sMoSe2-ICG NSs by covalently conjugating aminated indocyanine green (ICG) onto a single layer of molybdenum selenide nanosheets (sMoSe2 NSs). We first validate the sMoSe2-ICG NS agent for the PAI and PTT effect in vitro and then use it for highly-sensitive PAI guided highly efficient tumor PTT in vivo. The sMoSe2-ICG NS hybrid possesses several advantages for PAI/PTT applications: (1) the sMoSe2-ICG NSs have strong absorbance in the broad near-infrared (NIR) region, enabling a highly efficient PAI/PTT theranostic effect and the selection of the most widely used excitation wavelength of 808 nm for PTT; (2) the photothermal ability of ICG in sMoSe2-ICG NSs is augmented due to ICG aggregation induced fluorescence quenching and the re-absorbance of ICG fluorescence by sMoSe2 NSs, which further enhances the PAI/PTT theranostic effect. (3) The characteristic absorption peak of sMoSe2-ICG NSs is red-shifted compared to free ICG, resulting in a higher PAI signal-to-noise ratio (SNR) in vivo. Thus, combined with the good stability, high biocompatibility and minimal toxicity properties, the obtained sMoSe2-ICG NSs hybrid has bright prospects for use in future PAI/PTT clinical applications.

The NIR-II PA and PTT nanoparticle based on the IR-1061 dye would benefit early diagnosis and treatment of HCC.

Photoacoustic technology in combination with molecular imaging is a highly effective method for accurately diagnosing brain glioma. For glioma detection at a deeper site, contrast agents with higher photoacoustic imaging sensitivity are needed. Herein, we report a MoS2–ICG hybrid with indocyanine green (ICG) conjugated to the surface of MoS2 nanosheets. The hybrid significantly enhanced photoacoustic imaging sensitivity compared to MoS2 nanosheets. This conjugation results in remarkably high optical absorbance across a broad near-infrared spectrum, redshifting of the ICG absorption peak and photothermal/photoacoustic conversion efficiency enhancement of ICG. A tumor mass of 3.5 mm beneath the mouse scalp was clearly visualized by using MoS2–ICG as a contrast agent for the in vivo photoacoustic imaging of orthotopic glioma, which is nearly twofold deeper than the tumors imaged in our previous report using MoS2 nanosheet. Thus, combined with its good stability and high biocompatibility, the MoS2–ICG hybrid developed in this study has a great potential for high-efficiency tumor molecular imaging in translational medicine.Electronic supplementary materialThe online version of this article (10.1007/s40820-018-0202-8) contains supplementary material, which is available to authorized users.

A schematic illustration of CuS@BSA-RGD nanoparticle synthesis and the application of photoacoustic imaging in an orthotopic HCC model.

No abstract

A new dual mode competitive immunosensing platform for sensitive determination of α-fetoprotein (AFP) combined photoelectrochemical and electrochemical methods was designed on graphite carbon nitride and reduced graphene oxide (g-CN/rGO) conjugate support. To construct such versatile support, polyamidoamine dendrimer (PAAD) decorated graphene oxide (GO) as substrate was reduced via potentiostatic technology, and the prepared rGO-PAAD nanocomposite was utilized as matrix to immobilize g-CN and capture antigen, and as electron transporter to mediate electron transfer for enhancement of photoelectrochemical and electrochemical signals. And then, horseradish peroxidase labeled antibody was competitively captured onto sensing interface with free antigen in incubated solution. Photoelectrochemical signal originated from g-CN, an excellent photoactive material with large photo-induced electric response, and was amplified by rGO-PAAD nanocomposite. The resultant concentration positively related linear calibration range was from 1 pg/mL to 40 ng/mL with ultralow detection limit of 1 pg/mL. On the other hand, the enzyme-induced electrocatalytical signal amplification was produced by using hydroquinone as reactive substrate and horseradish peroxidase as reactive enzyme in existence of H 2 O 2 , which displayed a wide dynamic linear range from 0.1 ng/mL to 160 ng/mL with low detection limit of 0.1 ng/mL. Additionally, the satisfying selectivity, good reproducibility and high consistency of dual-signal outputs of this designed dual-responsive immunosensor demonstrated the promising application in developing sensitive and accurate immunosensor for clinical test and disease diagnosis.

No abstract