靶向成像在癌症的早期检测和精准诊断中扮演着越来越重要的角色。这一需求催生了对能够构建成影像探针的感知纳米材料的研究，以作为生物传感器。作为一种有价值的纳米探针，石墨烯量子点（GQDs）在双光子生物成像中显示出巨大潜力。然而，大多数经制备的GQDs表现出低的双光子吸收截面、窄的光谱覆盖范围和“一对一”信号转换模式，这严重阻碍了它们在敏感早期癌症检测中的广泛应用。在此，我们采用了一种多功能策略来制备用于靶向癌症成像信号放大策略的Sgc8c适配体修饰的混合体。在这项研究中，我们采用具有双光子成像性能的GQDs，以及硅氧化物纳米颗粒（SiO2 NPs）作为纳米载体，通过高负载GQD信号标记提供放大的识别事件，构建了基于双光子混合信号放大策略。因此，所得到的混合体（称为SiO2@GQDs）具有极强的荧光性能，量子产率高达0.49，具有出色的光稳定性和生物相容性，并且增强了明亮的双光子荧光，比裸GQDs（激发波长为760 nm；发射波长为512 nm）提高了2.7倍。此外，进一步修饰Sgc8c适配体对SiO2@GQDs混合体的结构和相应的双光子发射几乎没有破坏作用。因此，SiO2@GQDs-Sgc8c对目标细胞显示出特异性响应。此外，它还可用作信号放大的双光子纳米探针，用于靶向癌症成像，具有高特异性和高效性，与GQDs-Sgc8c或SiO2@GQDs相比，显示出明显的绿色荧光。这种信号放大策略对于准确早期肿瘤诊断具有很大潜力，并为临床应用中各种分析物的检测提供了新工具。

Targeted imaging is playing an increasingly important role in the early detection and precise diagnosis of cancer. This need has motivated research into sensory nanomaterials that can be constructed into imaging agents to serve as biosensors. Graphene quantum dots (GQDs) as a valuable nanoprobe show great potential for use in two-photon biological imaging. However, most as-prepared GQDs exhibit a low two-photon absorption cross-section, narrow spectral coverage, and "one-to-one" signal conversion mode, which greatly hamper their wide application in sensitive early-stage cancer detection. Herein, a versatile strategy has been employed to fabricate an aptamer Sgc8c-functionalized hybrid as a proof-of-concept of the signal amplification strategy for targeted cancer imaging. In this study, GQDs with two-photon imaging performance, and silica nanoparticles (SiO2 NPs) as nanocarriers to provide amplified recognition events by high loading of GQD signal tags, were adopted to construct a two-photon hybrid-based signal amplification strategy. Thus, the obtained hybrid (denoted SiO2@GQDs) enabled extremely strong fluorescence with a quantum yield up to 0.49, excellent photostability and biocompatibility, and enhanced bright two-photon fluorescence up to 2.7 times that of bare GQDs (excitation at 760 nm; emission at 512 nm). Moreover, further modification with aptamer Sgc8c showed little disruption to the structure of the SiO2@GQDs-hybrid and the corresponding two-photon emission. Hence, SiO2@GQDs-Sgc8c showed specific responses to target cells. Moreover, it could be used as a signal-amplifying two-photon nanoprobe for targeted cancer imaging with high specificity and great efficiency, which exhibits a distinct green fluorescence compared to that of GQDs-Sgc8c or SiO2@GQDs. This signal amplification strategy holds great potential for the accurate early diagnosis of tumors and offers new tools for the detection a wide variety of analytes in clinical application.