Long pepper (Piper longum) derived carbon dots as fluorescent sensing probe for sensitive detection of Sudan I

In this piece of work, microwave-assisted conversion of a natural precursor in to high-valued nano-scale material was carried out by a completely greener method. The fluorescent carbon dots prepared, designated as long pepper derived carbon dots (LPCDs), have been thoroughly characterized to explore the physical and chemical properties. The system exhibits excitation dependent emission behavior and from the optimal studies the excitation and emission wavelength of the system was found to be 330 nm and 455 nm respectively. On account of the superior fluorescent behavior of the LPCDs, it was successfully employed as a fluorescent sensing probe to detect Sudan I with good level of selectivity and sensitivity. This carcinogenic dye extensively used as food adulterant can impart several health issues. Food product safety is of high concern, therefore a simple facile and economical analytical method was proposed based on the fluorescence of LPCDs for this dye detection with satisfactory statistical parameters. A linear relationship was maintained in the range of 0 to 27.27 μM Sudan I with limit of detection of 0.92 μM. The quenching mechanism was studied and finally attributed to Förster resonance energy transfer (FRET) mechanism. In addition, the probe was effectively implemented for Sudan I detection in commercial chili powder samples with good level of recovery parameters.