title: Fluorescent Carbon Dot as Nanosensor for Sensitive and Selective Detection of Cefixime Based on Inner Filter Effect.
abstract: Here a simple and sensitive fluorescent assay for detecting Cefixime based on inner filter effect (IFE) has been proven, which is conceptually different from the previously reported CEF fluorescent assays. In this sensing platform, fluorescent carbon dots (CDs) were prepared by one-pot synthesis and was directly used as fluorophore in IFE. The method is based on the complexation reaction between cefixime and palladium ion in the presence of acidic buffer solution (pH 4). The Pd(II)-CEFcomplex was capable of functioning as a powerful absorber in IFE to influence the excitation of fluorophore (CDs). Production Pd(II)-CEFcomplex induced the absorption band transition from 310 to 400 nm, which resulted in the complementary overlap with the excitation spectra of CDs. Due to the competitive absorption, the excitation of CDs was significantly weakened, resulting in the quenching of CDs. The present IFE-based sensing strategy showed a good linear relationship from 0.2 × 10-6M to 8 × 10-6M (R2= 0.987) and provided an exciting detection limit of 0.5 × 10-7(3δ/slope). The proposed method has been successfully applied for the determination of cefixime in raw milk and human urine samples.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Urmia University, Urmia, Iran.
authors.forename: Farhad
authors.initials: F
authors.lastname: Akhgari
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Urmia University, Urmia, Iran. Samadi76@yahoo.com.
authors.forename: Naser
authors.initials: N
authors.lastname: Samadi
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, Urmia University, Urmia, Iran.
authors.forename: Khalil
authors.initials: K
authors.lastname: Farhadi
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000652:urine; D015374:Biosensing Techniques / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D020682:Cefixime / Q000378:metabolism / Q000652:urine*; D005453:Fluorescence; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D008892:Milk / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D000900:Anti-Bacterial Agents; D005456:Fluorescent Dyes; D002244:Carbon; D020682:Cefixime
keywords: Carbon quantum dot; Cefixime; Fluorescence detection; Inner filter effect; Sensor