Multifunctional nitrogen, silicon co-doped carbon dots with photothermal effect for the detection of rifampicin and Cr(Ⅵ)

As a new kind of fluorescent nanomaterial, carbon dots (CDs) have gained considerable focuses in regulating and improving their intrinsic properties. Some effective methods have been proposed and validated, like surface passivation and heteroatom doping in CDs. Herein, we have facilely fabricated the fluorescent nitrogen, silicon co-doped carbon dots (N,Si-CDs) by a one-pot solvothermal approach. N-[3-(Trimethoxysilyl)propyl]ethylenediamine and citrate were adopted as precursors for nitrogen, silicon, and carbon sources, respectively. Correspondingly, the formation of N,Si-CDs was affirmed via TEM, FT-IR, and XPS techniques. Further analysis of the optical properties was conducted using UV-vis spectrophotometry and fluorescence spectroscopy. Lastly, the prepared N,Si-CDs were utilized to investigate their sensing ability for rifampicin and Cr(Ⅵ) as well as photothermal effect. The detection linear range of this sensing probe for rifampicin was 0–18 μM, achieving the detection limit of 0.02 μM, besides the detection linear range for Cr(Ⅵ) was 0–130 μM, reaching the detection limit of 0.15 μM. Furthermore, the photothermal conversion efficiency (PCE) of N,Si-CDs was explored and calculated to be 43.45% with a favorable photothermal effect. Collectively, this research will provide novel insights for fluorescence sensing strategies and explore new proposals to develop CDs-based photothermal agents (PTAs) for cancer photothermal therapy (PTT).