title: Tuning photoluminescence and surface properties of carbon nanodots for chemical sensing.
abstract: Obtaining tunable photoluminescence (PL) with improved emission properties is crucial for successfully implementing fluorescent carbon nanodots (fCDs) in all practical applications such as multicolour imaging and multiplexed detection by a single excitation wavelength. In this study, we report a facile hydrothermal approach to adjust the PL peaks of fCDs from blue, green to orange by controlling the surface passivation reaction during the synthesis. This is achieved by tuning the passivating reagents in a step-by-step manner. The as-prepared fCDs with narrow size distribution show improved PL properties with different emission wavelengths. Detailed characterization of fCDs using elemental analysis, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy suggested that the surface chemical composition results in this tunable PL emission. Surface passivation significantly alters the surface status, resulting in fCDs with either stronger surface oxidation or N element doping that ultimately determine their PL properties. Further experiments suggested that the as-prepared orange luminescent fCDs (O-fCDs) were sensitive and specific nanosensing platforms towards Fe(3+) determination in a complex biological environment, emphasizing their potential practical applications in clinical and biological fields.
authors.affiliation: Key Laboratory of Sensing Technology and Biomedical Instruments (Guangdong Province), School of Engineering, Sun Yat-Sen University, Guangzhou, China. yichq@mail.sysu.edu.cn.
authors.forename: Zhaomin
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Sensing Technology and Biomedical Instruments (Guangdong Province), School of Engineering, Sun Yat-Sen University, Guangzhou, China. yichq@mail.sysu.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Key Laboratory of Sensing Technology and Biomedical Instruments (Guangdong Province), School of Engineering, Sun Yat-Sen University, Guangzhou, China. yichq@mail.sysu.edu.cn.
authors.forename: Yaning
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Key Laboratory of Sensing Technology and Biomedical Instruments (Guangdong Province), School of Engineering, Sun Yat-Sen University, Guangzhou, China. yichq@mail.sysu.edu.cn.
authors.forename: Lulu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Sensing Technology and Biomedical Instruments (Guangdong Province), School of Engineering, Sun Yat-Sen University, Guangzhou, China. yichq@mail.sysu.edu.cn.
authors.forename: Junying
authors.initials: J
authors.lastname: Chen
authors.affiliation: Key Laboratory of Sensing Technology and Biomedical Instruments (Guangdong Province), School of Engineering, Sun Yat-Sen University, Guangzhou, China. yichq@mail.sysu.edu.cn.
authors.forename: Changqing
authors.initials: C
authors.lastname: Yi
mesh_terms: D002244:Carbon / Q000737:chemistry*; D007501:Iron / Q000032:analysis* / Q000737:chemistry; D045663:Quantum Dots / Q000737:chemistry*
chemical_list: D002244:Carbon; D007501:Iron