A sensitive fluorescent sensor based on the photoinduced electron transfer mechanism for cefixime and ctDNA

Abstract

Cefixime is a third generation orally administered cephalosporin that is frequently used as a broad spectrum antibiotic against various gram-negative and gram-positive bacteria. In this study, a simple and sensitive fluorescent sensor for the determination of the cefixime and ctDNA was established based on the CdTe:Zn 2+ quantum dots (QDs). The fluorescence of CdTe:Zn 2+ QDs can be effectively quenched by cefixime in virtue of the surface binding of cefixime on CdTe:Zn 2+ QDs and the subsequent photoinduced electron transfer process from CdTe:Zn 2+ QDs to cefixime, in particular, the high sensitivity of QDs fluorescence emission to cefixime at the micromole per liter level, which render the cefixime-CdTe:Zn 2+ QDs system into fluorescence "OFF" status, then turn on in the presence of ctDNA. Furthermore, the Fourier transform infrared (FTIR) spectra of characteristic bands of C-N and N-H groups of cefixime endow evidence for the interaction of cefixime with CdTe:Zn 2+ QDs. The relative electrochemical behavior of the affinity of CdTe:Zn 2+ QDs for cefixime and ctDNA reveals the potential molecular binding mechanism. K E Y W O R D SCdTe:Zn 2+ QDs, cefixime, ctDNA, fluorescent sensor, photoinduced electron transfer

Study on novel fluorescent carbon nanomaterials in food analysis

“…Due to their large surface area, adjustable energy gap, and high electron exchange, graphene quantum dots are highly efficient compounds for photovoltaic devices. Also, due to their excellent electron-electron properties, low cost, high luminescence properties, and ability to perform processes, colloidal graphene dot colloids are widely used in solar cells as electron acceptors in the soluble phase (Cui et al, 2011;Miao et al, 2014;Yang et al, 2020).…”