Two-Photon Imaging of a Cellular Line Using Organic Fluorescent Nanoparticles Synthesized by Laser Ablation

• Published in: Particle & particle systems characterization Vol. 33; no. 2; pp. 101 - 109
• Main Authors: Aparicio-Ixta, Laura, Alba-Rosales, J. E., Ramos-Ortiz, Gabriel, Rodriguez, Mario, Pichardo-Molina, Juan L., Gutierrez-Juarez, Gerardo, Sabanero-Lopez, Myrna, Villavicencio, Liss Flores, Santillan, Rosa, Tellez-Lopez, Víctor M., Martinez-Fong, Daniel
• Format: Journal Article
• Language: English
• Published: Weinheim Blackwell Publishing Ltd 01.02.2016; Wiley Subscription Services, Inc
• Subjects: Absorption; Contrast agents; Excitation; Fluorescence; In vitro testing; Laser ablation; Lasers; microemulsion; Microscopy; Nanoparticles; organic nanoparticles; reprecipitation; two-photon microscopy
• ISSN: 0934-0866; 1521-4117
• DOI: 10.1002/ppsc.201500199

A comparative study of the optical properties of organic fluorescent nanoparticles fabricated by laser ablation (NPs‐LA), reprecipitation (NPs‐RP), and microemulsion (NPs‐ME) methods is presented. These nanoparticles contain a fluorene‐based p‐conjugated molecule (BT2). Distinctive electronic transitions are observed in samples due to the specific way in which the molecule BT2 is assembled in each type of nanoparticles; for instance, transitions involved in absorption and emission spectra of NPs‐LA result in blueshifting with respect to the molecular solution of BT2, whereas redshifting is observed in NPs‐RP and NPs‐ME. Further, the results show that under infrared excitation, the aqueous suspensions of NPs‐LA exhibit the highest fluorescence induced by two‐photon absorption (≈790 GM at 740 nm), as well as the best photostability, compared with aqueous suspensions of NPs‐RP and NPs‐ME. The nanoparticles synthetized by the three aforementioned methods are employed as exogenous agents for the visualization of human cervical cancer cell line (HeLa) using confocal and two‐photon microscopy. Under similar experimental conditions, it is found that microscopy images of the best quality are obtained with NPs‐LA. These results show that laser ablation is a suitable technique for the fabrication of organic fluorescent nanoparticles used as contrast agents for in vitro fluorescence microscopy. Organic fluorescent nanoparticles fabricated by laser ablation (NPs‐LA) are used as contrast agents for in vitro fluorescence microscopy. A comparative study of the optical properties of organic fluorescent nanoparticles fabricated by laser ablation (NPs‐LA), reprecipitation (NPs‐RP), and microemulsion (NPs‐ME) methods is presented. The results show that under infrared excitation, the aqueous suspensions of NPs‐LA exhibit the highest fluorescence induced by two‐photon absorption, the best photostability, and microscopy images of HeLa cells with the best quality.