Efficient two-photon luminescence for cellular imaging using biocompatible nitrogen-doped graphene quantum dots conjugated with polymersElectronic supplementary information (ESI) available: Experimental section, z-axis resolution of femtosecond laser, characterizations, TPE action/absolute cross sections, lifetime data, stability after photoexcitation or in physiological environments, cell viability and the amount of generated ROS, plots of dependence of TPL on excitation intensity and temperatu

• Main Authors: Wu, Ping-Ching, Wang, Jiu-Yao, Wang, Wen-Lung, Chang, Chia-Yuan, Huang, Chia-Hung, Yang, Kun-Lin, Chang, Jui-Cheng, Hsu, Chih-Li Lilian, Chen, Shih-Yao, Chou, Ting-Mao, Kuo, Wen-Shuo
• Format: Article
• Language: English
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c7nr06836k

Nitrogen-doped graphene quantum dot (N-GQD) nanomaterials conjugated with polyethylenimine (PEI)-polystyrene sulfonate (PSS)-anti-epidermal growth factor receptor (Ab EGFR ) antibody (N-GQD-PEI-PSS-Ab EGFR ) demonstrated impressive two-photon properties and stability, signifying that they can serve as an effective two-photon contrast agent in two-photon bioimaging. Furthermore, they provided high intensity, brightness, and signal-to-noise ratios at an ultra-low two-photon excitation (TPE) power level in an observation extending to a deep, three-dimensional depth. N-doped GQDs conjugated with polymers demonstrate impressive two-photon properties and stability, and can be used as a contrast agent in deep tissue bioimaging.