A Sensitive FRET Biosensor Based on Carbon Dots-Modified Nanoporous Membrane for 8-hydroxy-2′-Deoxyguanosine (8-OHdG) Detection with Au@ZIF-8 Nanoparticles as Signal Quenchers

Abstract

A sensitive fluorescence resonance energy transfer (FRET) biosensor is proposed to detect 8-hydroxy-2′-deoxyguanosine (8-OHdG), which is a typical DNA oxidation damage product excreted in human urine. The FRET biosensor was based on carbon dots (CDs)-modified nanoporous alumina membrane with CDs as fluorescence donors. Gold nanoparticles were encapsulated in zeolitic imidazolate framework-8 to form Au@ZIF-8 nanoparticles as signal quenchers. CDs and Au@ZIF-8 nanoparticles were biofunctionalized by 8-OHdG antibody. The capture of 8-OHdG on the membrane substrates can bring Au@ZIF-8 nanoparticles closely to CDs. With 350 nm excitation, the fluorescence of CDs was quenched by Au@ZIF-8 nanoparticles and FRET effect occurred. The quenching efficiency was analyzed. The limit of detection (LOD) was 0.31 nM. Interference experiments of the FRET biosensor showed good specificity for 8-OHdG detection. The biosensor could detect urinary 8-OHdG sensitively and selectively with simple sample pretreatment processes. It shows applicability for detecting biomarkers of DNA damage in urine or other biological fluids.

Carbon dot composites for bioapplications: a review

“…Currently, various mechanisms have been elucidated. Among them, three main mechanisms for PL quenching, namely Förster resonance energy transfer (FRET), 323–325 photoinduced electron transfer (PET) 326–328 and inner filtering effect (IFE), 329–331 have been widely used for the design and development of CD composite-based optical biosensors. On the other hand, in a typical “on–off–on” biosensor, the optical signal of CD composites undergoes a stepwise change: the PL is first turned off due to the interaction with a non-analyte quencher, then it could be restored in the presence of the target analyte; thus, the degree of recovery of the PL of the CD composites could be used for the detection and determination of the target analyte (Fig.…”

“…For instance, in Yan and co-workers’ study, glyoxylic acid-modified CDs (GA-CDs) were used as a FRET ratiometric fluorescent probe for the detection of Cu 2+ in aqueous solution. 388 Similarly, Chen et al also applied cyclam-functionalized CDs as a FRET nanoprobe for the detection of Cu 2+ and S. 2–389 In addition to the above examples, the detection of other important metal ions such as Ag + , Cu 2+ , Cr 6+ , and Pb 2+ has also been successfully realized with CD composite-based sensing platforms. 390–401…”

Insights into the Role of Oxidative Stress in Ovarian Cancer

“…H 2 O 2 and the hydroxyl radicals generated by the Fenton reaction have been shown to promote the transferrin-(Tf-) TfR1 axis, which induces DNA double-strand breaks in epithelial cells of the fallopian tube, which promotes the progression of OC [69]. The most common product of DNA oxidative damage is 8-hydroxy-2′-deoxyguanosine (8-OHdG), which is formed by guanine oxidation [70], and it is usually used as a biomarker of DNA damage as well as for assessing the risk associated with cancer progression [71][72][73]. In addition, 8-OHdG can induce C:G to A:T transformations, which are the most important somatic mutations in OC, breast cancer, lung cancer, and gastric cancer [74].…”

Advancements in 2D Materials Based Biosensors for Oxidative Stress Biomarkers

“…The sensor had a LOD of 0.31 nM and was able to detect the analyte molecule in human urine samples. 186 On a similar track, reports are available on detection of hydrogen peroxide as oxidative stress marker using optical transduction. Most commonly reported transduction systems are either color based or fluorescence based, with only a single report on SPR based optical technique for hydrogen peroxide detection.…”