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Sudan I is a cancer-causing chemical synthetic dye that is often illegally added to foods as a colorant. In this manuscript, based on molecularly imprinted polymers coated carbon dots (CDs@SiO2@MIPs), a novel fluorescence sensor is reported for the selective and sensitive determination of Sudan I. The sensor was prepared upon the surface of silica-coated carbon dots (CD@SiO2) by a one-pot sol-gel method using Sudan I as the template, 3-aminopropyl triethoxysilane (APTES) as the monomer, and tetraethyl orthosilicate (TEOS) as the crosslinker. Due to fluorescence resonance energy transfer, quenching occurred when CDs@SiO2@MIPs combined with Sudan I. The established sensor showed excellent recognition and performance for Sudan I with a wide linear range (1 to 120 μM) and low detection limit (0.61 μM). Furthermore, the sensor was successfully applied to determine Sudan I in chili powder and ketchup with recoveries from 89.7 to 101.7%. This work provides broad applications of fluorescence sensors based on CDs@SiO2@MIPs for the rapid analysis of food. [ABSTRACT FROM AUTHOR]

[Display omitted] • CDs@ZIF-8 was designed and synthesized for the detection of Sudan dyes. • The CDs@ZIF-8 demonstrated superior pH resistance when compared to CDs. • CDs@ZIF-8 offers higher sensitivity and wider detection range for Sudan I than CDs. • The method has been used in the detection of Sudan I in foodstuffs. In this manuscript, we synthesized CDs@ZIF-8 through a one-step, in-situ method by integrating green-emitting carbon dots (CDs) with zeolitic imidazolate framework-8 (ZIF-8). The resulting CDs@ZIF-8 was utilized as an ultrasensitive probe for detection, leveraging the inner filter effect. The analysis demonstrated the capability to detect Sudan dyes. Sudan I, for example, could be detected within a concentration range spanning from 0.25 to 70 μM, achieving a remarkable detection limit of 76.56 nM. This established method was effectively employed for detecting Sudan I in paprika. Compared with CDs, CDs@ZIF-8 exhibited a 3.32-fold increase in sensitivity and a wider detection range. This enhanced performance was attributed to the porous ZIF-8, which allowed for the enrichment of targets around CDs and avoided the aggregation of CDs. Additionally, embedding the CDs in ZIF-8 improved their pH stability. Our study provides a new approach for using CDs under limited conditions by leveraging metal–organic frameworks. [ABSTRACT FROM AUTHOR]