Because 2,4,6-trinitrophenol (TNP) and its analogues such as 2,4,6-trinitrotoluene (TNT) possess similar chemical structures and properties, the reliable and accurate detection of TNP from its analogues still remains a challenging task. In the present work, a selective and sensitive method based on the water-soluble silicon nanoparticles (SiNPs) for the determination of TNP was established. The SiNPs with good thermostability and excellent antiphotobleaching capability were prepared via a simple one-pot method. Compared with the synthesized time of other nanomaterials with respect to the detection of TNP, this method avoided a multistep and time-consuming synthesis procedure. Significantly, the fluorescence of the SiNPs could be remarkably quenched by TNP via an inner filter effect. A wide linear range was obtained from 0.02 to 120 μg/mL with a limit of detection of 6.7 ng/mL. The method displayed excellent selectivity toward TNP over other nitroaromatic explosives. The proposed fluorescent method was successfully applied to the analysis of TNP. Moreover, a straightforward and convenient fluorescent filter paper sensor was developed for the detection of TNP, providing a valuable platform for TNP sensing in public safety and security.

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The synthesis of dual-emissive carbon dots (CDs) with a longer emission wavelength by using a facile strategy is of great importance for the fabrication of ratiometric fluorescent nanoprobes. Herein, red/green dual-emissive carbon dots (RGDE CDs) were synthesized in one step using 2,5-diaminotoluene sulfate (DATS) as a carbon source. The as-prepared RGDE CDs not only exhibited dual emission fluorescence peaks (525 nm, 603 nm) at the single excitation wavelength of 370 nm, but also possessed good water solubility and excellent fluorescence stability. Moreover, the as-prepared RGDE CDs could be directly utilized as a ratiometric fluorescent probe for the determination of trace ONOO- due to the electron transfer process from ONOO- to the excited RGDE CDs. Under optimal conditions, the linear range was 0.03-60 μM with the limit of detection of 11.6 nM. Importantly, this RGDE CD probe could be applied for the detection of intracellular ONOO- with excellent biocompatibility and cellular imaging capability, indicating great promise in biomedical applications.