Publications Repository - Gdańsk University of Technology

Recently, the interest in applying fluorescent diamond particles (FDPs) containing nitrogen-vacancy (NV) centers for enhancing the mechanical and chemical properties of some materials, biological imaging, and sensing has been expanding rapidly. The unique properties of NV centers such as intensive, time-stable fluorescence, and an electron spin, which exhibits long coherence time and may be manipulated using external stimuli, such as pH, make them a perfect candidate for a quantum-effect-based sensing platform. However, monitoring of the local changes with the use of the nonmodified diamond particles has certain limitations; therefore, to enhance their sensing properties, in this article, the covalent functionalization of the FDPs’ surfaces with poly-L-Lysine (pLys) (NV-pLys) is presented. The FDPs’ surface is functionalized in an anhydrous environment, and successful attachment is confirmed by Fourier transform infrared spectroscopy (FTIR). As the pLys undergoes pH-triggered changes of conformation, it also induces changes in the diamonds’ surface charge, therefore modulating the fluorescence, and finally as a result enhances NV-pLys pH-sensitivity. Further investigation of the zeta potential, particle size, and contact angle reveals remarkable colloidal stability and superior wettability of the NV-pLys over a wide range of pH, which also may significantly affect NV-pLys biocompatibility. These findings open new possibilities for the construction of biocompatible, stable, and highly sensitive nanosensors.

Authors

• dr inż. Monika Janik link open in new tab ,
• Maciej Głowacki link open in new tab ,
• dr hab. inż. Mirosław Sawczak,
• dr Anna Wcisło,
• Dr Paweł Niedziałkowski,
• dr inż. Kacper Jurak link open in new tab ,
• dr inż. Mateusz Ficek link open in new tab ,
• dr hab. inż. Robert Bogdanowicz link open in new tab