Fabrication of mesoporous nanoprobe with molecularly imprinted fluorescent carbon dots embedded within silica network for the selective and sensitive detection of aspirin in ground water samples

In this work, a highly selective and sensitive protocol has been developed to detect aspirin (ASP) by using mesoporous silica nanoprobe equipped with molecular imprints and fluorescent carbon dots (ms-MIP-FCDs). The fabrication of nanoprobe is based on the reprocessing of rice straw to fluorescent carbon dots (FCDs) and their amalgamation with molecular imprinting within mesoporous silica network (ms). The molecular imprints for ASP were introduced via sol gel process. The nanoprobe displayed spectrofluorimetric signal due to photoinduced electron transfer between ms-MIP-FCDs and ASP. The synergistic action of mesopores, molecular imprints, and FCDs makes the spectrofluorimetric recognition of ASP quick (in 5 min), sensitive (LOD = 1.16 nM), and selective in the presence of potential competing interferents (such as salicylic acid, methyl salicylate, salsalate, 5methylsalicyldehyde, naproxen, ketoprofen, diclofenac, mefenamic acid, carbamazepine, and levofloxacin). Furthermore, the method can be successfully applied to detect the ASP from ground water samples with the recoveries in the range of 94.1-104.2% and good precision (relative standard deviation (RSD) < 6.0%). The prepared fluorescent probe also displayed excellent performance with enhanced reusability/durability.